A conservatory added to an existing house is, in almost all ordinary cases, standard-rated at 20% VAT — and this remains true even where the extension is specifically intended to help a disabled household member, which is a genuinely common and costly misconception.

The default position: standard-rated at 20%

HMRC’s VAT Notice 708, which governs VAT on buildings and construction, treats most work on an existing residential building — including adding a conservatory — as standard-rated. The zero and reduced VAT rates available in construction are targeted at specific categories of work, principally the construction of genuinely new dwellings, rather than extensions and alterations to a house that already exists. A conservatory is, in VAT terms, work to an existing building, not the construction of a new one, which is why it falls on the standard-rated side of that line by default.

Why new-build construction is treated differently

Zero rating under Notice 708 is specifically aimed at the construction of new qualifying dwellings and certain communal residential or charitable buildings. The notice illustrates the boundary with a specific example: where a conservatory supplier only gains access to a property after it has already been sold to a house buyer, that conservatory installation is treated as work to an existing building, not work carried out “in the course of construction” of the house itself — and so cannot be zero-rated, even though the house it’s attached to was itself a new build only shortly beforehand.

Why the separate disability VAT relief doesn’t cover conservatories

UK VAT law does provide a specific zero rate for certain building work carried out for disabled people — but HMRC’s own guidance on this relief explicitly lists conservatories among the types of work that are excluded. The guidance specifically states that extending or adapting a property to provide a conservatory, carer’s room, office or living room cannot be done VAT-free under this relief, even where the work is genuinely connected to a resident’s disability. There is one specific exception worth knowing: an extension built specifically to provide a downstairs bathroom can qualify for the relief, because the bathroom adaptation itself is separately eligible — but a conservatory built for general living space, even in a home with a disabled resident, does not benefit from this relief.

Where a reduced rate can genuinely apply

The 5% reduced VAT rate under Notice 708 is aimed at specific categories, including converting a non-residential building into a dwelling, renovating or altering residential premises that have been empty for a qualifying period, and installing certain energy-saving materials. A standard conservatory added to an already-occupied home does not fall into any of these categories in the ordinary case — the reduced rate is a narrow exception, not a general discount available for most home improvement work.

What to check when comparing conservatory quotes

• Confirm whether a quoted price is VAT-inclusive or exclusive — and if a supplier is quoting a reduced or zero rate, ask them to explain specifically which HMRC category they believe applies, since the default position is standard-rated.
• Don’t assume a disability-related need for the space changes the VAT position — HMRC guidance is specific that it doesn’t, for a conservatory itself.
• If your project genuinely involves converting a non-residential building, or renovating a long-empty property, it’s worth checking the specific reduced-rate conditions with your installer or an accountant, since these categories do carry real savings where they apply.

FAQs

Is there any way to get a conservatory built VAT-free?

For an ordinary extension to an existing, currently-lived-in home, no — the standard rate applies. The narrow exceptions in VAT law are aimed at new dwelling construction, certain conversions and renovations of long-empty homes, not standard home extensions.

Does it matter if the conservatory is needed for medical reasons?

No, specifically for conservatories. HMRC’s disability VAT relief explicitly excludes conservatories from its scope, even where the extension is connected to a resident’s disability, with the narrow exception of a downstairs bathroom addition.

Should I ask my installer to itemise VAT on my quote?

Yes — a clear, itemised quote showing the VAT treatment applied, and the reasoning if anything other than the standard 20% rate is being charged, is worth requesting before signing any contract.

Sources

This guide draws on the following primary sources, current as of 16 September 2026:

• gov.uk: Buildings and construction (VAT Notice 708)
• gov.uk: VAT relief on certain building work if you have a disability

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not legal advice on any specific property — always confirm with your Local Planning Authority.

Most conservatories fall under a specific minor development exemption from the Community Infrastructure Levy — but the exemption isn’t automatic, and losing it by combining works or missing a form can turn a straightforward extension into an unexpectedly expensive one.

What the Community Infrastructure Levy actually is

The Community Infrastructure Levy (CIL) is a charge that local authorities in England and Wales can choose to apply to new development, used to help fund local infrastructure such as roads, schools and green space. Not every council charges CIL, and where it is charged, the rate and rules are set out in that specific authority’s own charging schedule — there is no single flat national rate, which is why checking locally, rather than assuming a figure from elsewhere applies, matters.

The minor development exemption most conservatories fall under

Government guidance is explicit that residential extensions under 100 square metres, which are not part of a development creating a new dwelling, are already exempt from the levy under the minor development exemption. The overwhelming majority of domestic conservatories sit comfortably under this threshold, meaning most homeowners building a conservatory as a standalone extension to an existing house will not face a CIL charge at all.

Where a conservatory can lose that exemption

The exemption is tied to the nature of the development, not simply the physical size of the conservatory in isolation. Guidance specifically notes that a structure can become liable if it forms part of a wider development that also creates a new dwelling, or contributes to a project’s net additional floor space reaching 100 square metres or more when combined with other works. In practice, this matters most where a conservatory is being built as one part of a larger scheme — for example, alongside a loft conversion, a garage conversion, or another extension on the same property — since it’s the combined additional floor space across the whole scheme that’s assessed, not the conservatory alone in isolation from everything else being built.

Checking your council’s charging schedule before you design

Because CIL is set locally, and some council areas don’t charge it at all, the practical first step is checking your own local planning authority’s current charging schedule, rather than assuming either that CIL definitely won’t apply (because most conservatories are exempt) or that it definitely will. This is a genuinely different question from planning permission itself — a project can be entirely permitted development, requiring no planning application at all, and still, in principle, be a development that needs a CIL exemption claim if it’s large enough or combined with other works.

Why the paperwork matters even when you’re confident you’re exempt

A recurring, costly mistake in CIL cases generally is assuming an exemption applies automatically because a project is small, without actually submitting the required exemption claim form to the local authority before starting work. CIL exemptions typically need to be formally claimed and confirmed in writing before development begins — starting work without that confirmation in place, even for a project that would genuinely have qualified, can in some circumstances result in the exemption being lost and the full levy becoming payable. This is a case where the process, not just the underlying facts, determines the outcome, so checking the exact procedure with your local planning authority before work starts is worth the (usually free) time it takes.

FAQs

Do I need to do anything if my conservatory is clearly under 100 square metres and stands alone?

Even where you’re confident the minor development exemption applies, it’s worth confirming directly with your local planning authority whether any formal notification or claim is expected before work starts, since local process can vary.

Does CIL apply on top of planning permission fees?

Where it applies, CIL is a separate charge from the planning application fee itself, and from any Building Regulations fees — it’s specifically an infrastructure levy, assessed and charged independently of those other costs.

Do all councils in England charge CIL?

No. It’s a local choice, and coverage varies — some authorities charge it, others don’t, which is why checking your own council’s specific charging schedule is the only reliable way to know your local position.

Sources

This guide draws on the following primary sources, current as of 16 September 2026:

• gov.uk: Community Infrastructure Levy — guidance

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not legal advice on any specific property — always confirm with your Local Planning Authority.

Right to light is an old, still-active area of English property law: a neighbour whose window has received daylight for twenty years or more without interruption can hold a genuine legal right to that light, which a nearby conservatory build needs to respect.

Where this legal right actually comes from

The modern right to light rests on section 3 of the Prescription Act 1832, which took a long-standing common law principle and put it into statute. The Act provides that where light has been actually enjoyed through a window or other aperture for the full period of twenty years without interruption, that right becomes “absolute and indefeasible” — meaning it becomes a settled legal right, not merely a continuation of an informal arrangement. This applies to dwelling houses, workshops and other buildings, and the right is secured unless the twenty years of enjoyment happened with express written consent from the neighbouring landowner, which prevents the right from crystallising.

What the right actually protects — and what it doesn’t

A right to light is not a right to an unobstructed view, and it is not a right to full daylight at every point in a room. It is generally understood as protecting enough light to allow a room to be used for its ordinary purpose — a legal standard focused on adequacy for reasonable use, not an entitlement to the maximum possible light a window has ever received. This distinction matters: a conservatory that measurably reduces the amount of light reaching a neighbour’s window doesn’t automatically breach their right to light, unless it reduces that light below the level needed for ordinary use of the affected room.

How this can affect a conservatory build in practice

A conservatory is exactly the kind of structure — often built close to a boundary, sometimes at a height or footprint that changes over the original single-storey norm — that can realistically raise a right to light question for a neighbouring property, particularly if the neighbour’s own windows are close to the shared boundary and have received consistent daylight for a long period. This is a genuinely separate legal question from planning permission: a project can have full planning consent (or fall entirely within permitted development) and still infringe a neighbour’s right to light, because planning law and this area of property law protect different interests and are assessed under entirely different tests.

How right to light issues are usually identified and resolved

For larger or more sensitive projects, a right to light assessment can be carried out by a specialist surveyor, who can model the likely impact of a proposed structure on a neighbouring property’s light before building work starts — catching a potential problem at the design stage rather than after a neighbour raises an objection, or worse, a legal claim, once the conservatory is built. Where a genuine issue is identified, resolution can range from a design adjustment (reducing height, footprint or roof pitch, for example) through to a neighbour agreeing to release or vary their right, sometimes in exchange for a payment, formalised through a deed.

What to check before finalising a design near a boundary

• How close the proposed conservatory will sit to a neighbouring property’s windows, and their orientation relative to the sun.
• Whether the neighbouring windows appear to be long-established, which increases the likelihood a twenty-year right may already have accrued.
• Whether a right to light assessment is proportionate for the scale and location of your specific project.
• Whether informal early conversation with the neighbour, before formal notices or applications, might resolve any concern more simply than a later dispute.

FAQs

Does right to light apply automatically to every window?

No. It only arises after twenty years of uninterrupted enjoyment of light through a specific window or aperture, without written consent from the neighbouring landowner having been given during that period.

Is right to light the same thing as loss of view?

No, and this is a common confusion. There is generally no legal right to a view in English law; right to light is specifically about the amount of daylight reaching a window, not what can be seen through it.

Can a neighbour stop my conservatory build entirely over right to light?

In serious, unresolved cases, a court can grant an injunction requiring a structure to be altered or even removed, though in practice many disputes are resolved through design changes or a negotiated agreement before reaching that point.

Sources

This guide draws on the following primary sources, current as of 16 September 2026:

• legislation.gov.uk: Prescription Act 1832, section 3

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not legal advice on any specific property — always confirm with your Local Planning Authority.

The Party Wall Act 1996 is a completely separate legal process from planning permission and Building Regulations — it exists specifically to manage disputes between neighbours over work affecting a shared wall, a new boundary wall, or excavation near a neighbouring building.

What the Party Wall Act actually covers

The Party Wall etc. Act 1996 sets a procedure for dealing with disagreements between neighbouring property owners over specific categories of work: work directly to an existing party wall shared between two properties, building a new wall at or astride a boundary, and excavation work near a neighbouring building’s foundations. A conservatory built close to, or against, a boundary wall can bring one or more of these categories into play, depending on exactly what the build involves.

It is worth being clear that this Act operates independently of planning permission and Building Regulations — a project can be entirely compliant with permitted development rules and Building Regulations, and still separately require notice under the Party Wall Act, because the two systems test different things. The Planning Portal’s own guidance is explicit that there will be cases where both frameworks apply to the same piece of work.

The specific notice periods that apply

Gov.uk’s explanatory booklet on the Act sets out different minimum notice periods depending on the category of work:

• Work to an existing party wall (Section 2 of the Act): at least two months‘ notice before the planned start date.
• Building a new wall at the boundary (Section 1): at least one month‘s notice before the planned start date.
• Excavation near a neighbouring building (Section 6): at least one month‘s notice before the planned start date.

Work cannot begin until these notice periods have run their course, unless the adjoining owner gives written consent to an earlier start. Once served, a notice remains valid for one year, so there’s a practical limit on how far in advance it makes sense to serve notice if your build timeline is still uncertain.

How this differs from planning permission and Building Regulations

Planning permission (or permitted development) assesses whether a structure is allowed at all, from a land-use perspective. Building Regulations assess whether the structure itself is built safely and to the required technical standard. The Party Wall Act does neither of these things — it exists purely to manage the relationship, and any dispute, between neighbours over work that could physically affect a shared structure or a neighbour’s foundations. You can have full planning permission and full Building Regulations sign-off and still be in breach of your obligations under the Party Wall Act if you haven’t served the required notice.

What happens after you serve notice

An adjoining owner who receives notice can consent to the work, stay silent (which after the notice period can be treated similarly to a dispute in some circumstances), or formally dissent. Where there is a dispute, the Act provides a mechanism for appointing a surveyor, or surveyors, to resolve it — this is a structured, established process rather than an informal negotiation, and it exists specifically so that neighbour disputes over this kind of work don’t need to default straight to court.

What happens if you skip it

Carrying out notifiable work without serving the required notice doesn’t automatically stop the project succeeding, but it removes the legal protections and structured dispute process the Act provides, and can expose you to a neighbour seeking an injunction or damages if the work causes them a problem. Given the notice periods involved are measured in weeks, not months of delay to an overall project, building them into your planning timeline from the outset is generally the simpler course.

FAQs

Does the Party Wall Act apply if my conservatory won’t touch the boundary at all?

If none of the specific triggers apply — no work to a shared wall, no new wall at the boundary, and no excavation near a neighbouring building’s foundations — the Act may not be engaged at all. Whether a specific project triggers it depends on the exact proximity and nature of the work, which is worth checking directly if there’s any doubt.

Can my neighbour refuse to let the work go ahead entirely?

The Act’s dispute resolution process is designed to manage disagreements about how work is carried out, rather than giving a neighbour a general veto over otherwise lawful work — but a genuine, unresolved dispute can still cause real delay and cost.

Do I need a solicitor to serve a party wall notice?

Not necessarily for the notice itself, but many homeowners involve a party wall surveyor at an early stage, particularly for anything beyond the most straightforward projects, given the Act’s process for resolving disputes is a specific, structured one.

Sources

This guide draws on the following primary sources, current as of 16 September 2026:

• gov.uk: The Party Wall etc. Act 1996 — explanatory booklet
• Planning Portal: What is the Party Wall Act?

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not legal advice on any specific property — always confirm with your Local Planning Authority.

If your conservatory’s windows or doors are being replaced, that work is normally subject to Building Regulations — and the certificate you’re given afterwards is the paper trail proving it was done, and signed off, correctly.

Why replacement glazing is controlled at all

Replacing windows, doors or roof glazing is not simply a like-for-like swap in the eyes of Building Regulations — the replacement needs to meet current thermal performance and safety glazing standards, even where the original installation predates those standards. This applies to conservatory glazing just as much as to the main house, which is why a seemingly simple job like replacing a failed double-glazed unit can still trigger a formal compliance requirement.

What a Competent Person Scheme actually does

Gov.uk’s guidance on Competent Person Schemes explains that members of these schemes can self-certify certain types of building work, meaning you do not have to get a local council or private approved building inspector to separately check the work. This matters practically: without self-certification, you would otherwise need to arrange and pay for a building control inspection yourself to get the same compliance confirmation. Different schemes cover different trades, so it’s worth choosing an installer registered with a scheme that actually supports the type of work being carried out on your conservatory.

FENSA specifically, and how it fits in

FENSA (the Fenestration Self-Assessment Scheme) is the best-known Competent Person Scheme covering window and door installers in England and Wales, and is the scheme most homeowners will encounter when replacing conservatory glazing specifically. An installer registered with FENSA (or an equivalent scheme) can certify their own work as compliant with Building Regulations, notify the local authority on your behalf, and issue you a certificate confirming this — without a separate building control visit being required.

What you should receive once the work is finished

After a compliant installation, you should be issued a certificate confirming the work has been notified and certified under the relevant Competent Person Scheme. This document matters beyond the moment of installation:

• It’s evidence for a future buyer’s solicitor that replacement glazing was carried out lawfully, avoiding delays or retrospective certification costs when you come to sell.
• It may be requested by your home insurer in the event of a claim connected to the glazing.
• It confirms the specific safety and thermal standards the installation was actually tested against.

Keep this certificate with your other property paperwork, in the same place as any planning permission or building regulations records for the conservatory itself — missing documentation is a genuinely common snag in property sales involving a conservatory (see our separate guide on buying a house with a conservatory).

If your installer isn’t registered with a scheme

Using an installer who isn’t part of a relevant Competent Person Scheme doesn’t automatically mean the work is unlawful, but it does mean the self-certification route isn’t available to them — and Building Regulations compliance still needs to be demonstrated some other way, typically by applying to building control directly and paying for an inspection. This is worth factoring into any quote comparison: a lower quote from a non-registered installer may not include the cost, or the hassle, of arranging that separate building control sign-off yourself.

FAQs

Does every conservatory glazing job need a FENSA certificate?

Most replacement glazing work is notifiable under Building Regulations, but the specific requirements can depend on the exact scope of work. If in doubt, ask your installer directly which scheme they’re registered under and confirm before work starts, rather than after.

Is FENSA the only Competent Person Scheme covering windows and doors?

No, other schemes also cover this type of work. What matters is that your installer is registered with a scheme that actually covers the specific trade and work being carried out, not necessarily FENSA by name.

What if I’ve lost my certificate from a past installation?

It’s usually possible to request a duplicate or confirmation from the relevant scheme, since records are typically held centrally rather than only by the original installer, who may no longer be trading.

Sources

This guide draws on the following primary sources, current as of 16 September 2026:

• gov.uk: Building regulations — Competent Person Schemes

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not legal advice on any specific property — always confirm with your Local Planning Authority.

Two genuinely different legal routes exist for regularising a conservatory built without permission — and a recent law change has extended how long enforcement action can be time-barred.

This article covers regularising an unauthorised conservatory or extension in England. It is general information, not planning advice for your specific situation – if you’re dealing with this directly, a planning consultant or solicitor experienced in enforcement matters is worth the cost.

Why this situation comes up

It’s a more common problem than people expect: a conservatory that turns out to exceed permitted development limits, was built without the planning permission it actually needed, or was put up by a previous owner without proper consent. Sometimes it only surfaces when you come to sell, and a buyer’s conveyancer or lender flags a mismatch between what’s on the ground and what the planning records show.

Option one: apply for retrospective planning permission

English planning law specifically allows you to apply for planning permission for development that’s already been carried out – this is a genuine, legitimate route, not a loophole. The council has to assess a retrospective application on exactly the same planning merits as it would have assessed the same proposal before you built it; it cannot refuse simply because the work is already done, though in practice the fact that it exists doesn’t guarantee approval either. If the retrospective application is refused, the council can then take enforcement action requiring alteration or removal – so this route carries genuine risk if the structure wouldn’t have been approved in the first place, and it’s worth an honest planning assessment before applying, rather than applying and hoping.

Option two: a Certificate of Lawfulness, but only once enough time has passed

This is a different legal route entirely, and it’s commonly confused with retrospective permission. A Certificate of Lawfulness of Existing Use or Development doesn’t ask the council to judge the planning merits of the structure at all – it’s a factual and legal determination confirming that the council can no longer take enforcement action because the relevant time limit has passed. To succeed, you generally need to provide solid evidence – dated photographs, utility bills, statutory declarations from neighbours, or similar – proving the structure has existed continuously, without a break, for the full relevant period. If you can’t demonstrate that continuity, or the time limit hasn’t actually passed yet, this route isn’t available to you, and retrospective planning permission is your only option.

The enforcement time limit itself has recently changed

This is a genuinely important point to check carefully rather than assume. Historically, most unauthorised building work in England became immune from enforcement action after four years. Changes introduced through the Levelling Up and Regeneration Act 2023 have extended this time limit to ten years for most types of unauthorised development, bringing building work into line with the longer period that already applied to unauthorised changes of use. Transitional rules govern exactly how this applies depending on when the unauthorised work took place, so don’t assume an older four-year rule of thumb still protects work carried out some years ago – check the current position, including any transitional provisions that might apply to your specific dates, with your council or a planning professional before relying on any time limit.

What happens if you do nothing

Leaving an unauthorised structure unresolved doesn’t make the underlying problem go away, even once enforcement action is technically time-barred, because without a formal Certificate of Lawfulness, there’s no official record confirming that status. This routinely surfaces at the worst possible time – during a sale, when a buyer’s solicitor or mortgage lender wants clarity and isn’t willing to simply take your word for it.

Indemnity insurance: a workaround, not a fix

In some cases, particularly where enforcement risk is genuinely low but no formal certificate has been obtained, conveyancers sometimes suggest indemnity insurance as a way to satisfy a buyer or lender rather than formally regularising the structure. This can work in the right circumstances, but it’s a commercial workaround rather than a legal resolution – it doesn’t make the structure lawful, it simply insures against the financial consequences if enforcement action is ever taken, and not every lender or buyer will accept it as sufficient. Getting proper retrospective permission or a Certificate of Lawfulness, where either is genuinely available to you, resolves the underlying issue rather than just insuring around it.

Practical first steps

• Establish exactly what was built, when, and what (if any) permission was obtained at the time;
• Gather any dated evidence you have of the structure’s history, in case a Certificate of Lawfulness becomes relevant;
• Get an honest, early assessment of whether the structure would likely pass on its planning merits before applying for retrospective permission;
• Don’t wait until you’re trying to sell to address it – resolving it in advance avoids a rushed, pressured process during a transaction.

FAQs

What’s the difference between retrospective planning permission and a Certificate of Lawfulness?

Retrospective planning permission asks the council to judge the structure on its planning merits, with a real risk of refusal and enforcement action if it wouldn’t have been approved. A Certificate of Lawfulness doesn’t judge the merits at all – it’s a factual and legal determination that enforcement action is now time-barred, and it’s only available once you can prove the structure has existed continuously for the full relevant period.

How long does an unauthorised conservatory need to stand before it becomes immune from enforcement?

Historically this was four years for most unauthorised building work in England. Changes introduced through the Levelling Up and Regeneration Act 2023 extended this to ten years for most types of unauthorised development, with transitional rules governing exactly how it applies depending on when the work took place.

Sources

This guide draws on the following primary sources, current as of 15 September 2026:

• Planning Portal, retrospective planning permission – planningportal.co.uk
• GOV.UK, planning enforcement guidance – gov.uk/guidance/ensuring-effective-enforcement
• Legislation.gov.uk, Levelling-up and Regeneration Act 2023 – legislation.gov.uk
• Legislation.gov.uk, Town and Country Planning Act 1990 – legislation.gov.uk

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write.

Conservation area status and listed building status are separate legal protections with different consent requirements — and unauthorised work to a listed building can be a criminal offence, not just a planning breach.

This article covers conservation areas and listed buildings in England, where separate rules from the Planning (Listed Buildings and Conservation Areas) Act 1990 apply alongside ordinary planning law. This is general information – always check with your local planning authority’s conservation team before designing a conservatory for a property in either category.

Two separate regimes, often confused with each other

Conservation area status and listed building status are different legal protections, and it’s genuinely common for people to assume they’re roughly the same thing, or that one implies the other. They don’t – a property can be in a conservation area without being listed, can be listed without being in a conservation area, or, in plenty of cases, can be both at once, in which case both sets of rules apply together.

Conservation areas: permitted development rights are already tighter, even without an Article 4 direction

Being in a conservation area – an area a council has formally designated for its special architectural or historic character – automatically brings some extra restrictions on permitted development, built into the General Permitted Development Order itself, separate from any specific Article 4 direction a council might additionally apply. In practice, this generally means certain types of work that would be permitted development on an ordinary house elsewhere become more restricted, or need particular attention to materials and visibility from the street, within a conservation area. Whether your specific proposed conservatory needs full planning permission because of conservation area status, or still qualifies under permitted development with some added conditions, depends on its exact position, size and visibility – this is genuinely a case where a quick check with the council before you commission designs can save real time and money.

Listed buildings: a stricter, separate consent regime

Listed building status is a different and generally more demanding protection. If a building is listed, Listed Building Consent is required for any works that would affect its character as a building of special architectural or historic interest – and this isn’t limited to external changes; internal alterations can need consent too if they affect the building’s special interest. Critically, ordinary permitted development rights that a homeowner elsewhere might rely on for a modest conservatory generally do not apply in the same way to listed buildings; several permitted development classes specifically exclude works affecting a listed building. In practice, this means a conservatory added to a listed house is very likely to need Listed Building Consent regardless of how modest the design is, and separately, planning permission may also be required depending on the specifics.

Carrying out unauthorised work to a listed building is a criminal offence

This is worth being genuinely clear about, because it’s a meaningfully different legal position from an ordinary planning breach. Unauthorised works affecting a listed building, carried out without the necessary Listed Building Consent, can be a criminal offence, not simply a civil planning enforcement matter – a distinction that doesn’t apply to most permitted-development-related planning issues on an unlisted property. If you own or are buying a listed building and are considering any alteration, get proper advice and the necessary consent before any work starts, rather than treating it as routine home improvement paperwork.

The “curtilage” trap

Listed building protection doesn’t necessarily stop at the walls of the listed structure itself. Buildings, walls or structures within the curtilage of a listed building – broadly, its immediate grounds or setting, as it stood at a defined historic date – can also be treated as part of the listed building for consent purposes, even if that specific structure was never separately listed. This means a proposed conservatory sited within the grounds of a listed house can potentially need Listed Building Consent because of its relationship to the main building, even though the conservatory itself would obviously be a modern addition. Whether curtilage listing applies to a specific structure or position is a genuinely technical question, and one worth raising directly with the council’s conservation officer rather than assuming either way.

Practical steps

• Establish clearly, in writing from the council, whether your property is listed, in a conservation area, both, or neither, before you commission any design work;
• Speak to the local planning authority’s conservation officer early – heritage-sensitive design and materials expectations are usually stricter, and early input can shape a design that has a realistic chance of consent;
• Never start work affecting a listed building without confirmed Listed Building Consent, given the criminal offence risk;
• If your property is listed, check whether curtilage listing might extend protection to where you’re proposing to build, even away from the main building itself.

FAQs

Does conservation area status automatically mean I need full planning permission for a conservatory?

Not automatically, but conservation area status brings extra restrictions on permitted development, built into the General Permitted Development Order itself, separate from any specific Article 4 direction. Whether your project needs full planning permission depends on its exact position, size and visibility, so it’s worth checking with the council before commissioning designs.

Could my conservatory need Listed Building Consent even if it doesn’t touch the listed building?

Possibly. Buildings, walls or structures within the curtilage of a listed building can be treated as part of the listed building for consent purposes, even if they were never separately listed – so a conservatory sited in the grounds of a listed house can potentially need Listed Building Consent because of its relationship to the main building.

Sources

This guide draws on the following primary sources, current as of 15 September 2026:

• Historic England, listed buildings and consent – historicengland.org.uk
• Planning Portal, conservation areas and listed buildings – planningportal.co.uk
• Legislation.gov.uk, Planning (Listed Buildings and Conservation Areas) Act 1990 – legislation.gov.uk

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write.

Since 2011 many pipes that look like private garden drains are legally public sewers, and building over or near one without your water company’s agreement can force costly alterations later.

This article covers building over or near a public sewer in England and Wales. It is general information, not a substitute for checking with your specific water and sewerage company before you build.

Why this catches more people out than it used to

On 1 October 2011, ownership of a large number of previously private drains and sewers in England and Wales transferred to water and sewerage companies, as part of a nationwide transfer of private sewers. The practical effect is that a pipe running through or near your garden that you might reasonably assume is a private drain – something you’re free to build over without asking anyone – may now legally be a public sewer, owned and maintained by your water company. This significantly increased the number of homeowners who need to check before planning a conservatory or extension near what looks like an ordinary garden drain.

What Building Regulations require

Building Regulations Part H covers drainage and waste disposal, and includes specific requirements about building over or near an existing sewer, precisely because a structure sitting on top of a sewer makes it much harder – sometimes impossible without demolition – for the water company to access it for maintenance, repair or replacement. Before building over or near a public sewer, you’re generally expected to check with your water and sewerage company, and in many cases will need their formal agreement before work goes ahead, not just a building control sign-off.

A common point of confusion: two very different “section 106”s

The formal agreement covering building over or near a public sewer is sometimes referred to using a section number from the Water Industry Act 1991. This causes genuine confusion because property buyers and self-builders more often encounter “section 106” in a completely different context – section 106 agreements under the Town and Country Planning Act 1990, which relate to developer contributions on larger planning applications, and have nothing to do with drainage. If you see “section 106” mentioned in relation to your conservatory project, check which piece of legislation is actually being referred to, since the two are entirely unrelated despite sharing a section number.

What the process actually involves

You contact your local water and sewerage company (which company covers you depends on where you live, and is separate from whoever bills you for water use in some areas) and provide details of the proposed structure and its position relative to the sewer. The water company assesses the risk and may:

• Grant a build-over or build-near agreement, often with conditions – for example, a specific foundation design that spans the pipe rather than bearing directly on it, or a requirement to preserve access points such as manholes or rodding eyes;
• Refuse permission to build directly over the sewer and instead require the sewer to be diverted at the owner’s cost before the structure can proceed;
• Ask for further information, such as a CCTV survey of the pipe, before making a decision.

Even if your conservatory is positioned near rather than directly over a sewer, it’s worth checking with the water company rather than assuming distance alone makes it exempt – how close is “close enough to matter” depends on factors like the pipe’s depth and diameter, which is exactly why it’s a case-by-case assessment rather than a fixed rule you can apply yourself.

What happens if you skip this step

Building over a public sewer without the necessary agreement can leave you facing a requirement to alter or remove the structure at your own cost later, if the water company needs access and finds the unauthorised structure in the way. It’s also a real practical problem when selling: a standard drainage and water search carried out during conveyancing (commonly a CON29DW search) will typically reveal the presence of a public sewer and flag any unresolved build-over issue, which can make a property difficult to sell or mortgage until it’s sorted out. It’s considerably cheaper and less stressful to check and get agreement before you build than to resolve a problem after the fact.

Practical first steps

• Check whether there’s a public sewer on or near your property – your water company can usually provide sewer location plans on request;
• Contact your water and sewerage company before finalising your conservatory’s design and position, not after;
• Factor in the possibility of needing a specific foundation design, or in rarer cases a sewer diversion, when budgeting and planning your timeline;
• Keep any written agreement from the water company with your other property paperwork – you may need to produce it if you sell.

FAQs

How do I find out if there’s a public sewer near where I want to build my conservatory?

Contact your water and sewerage company – they can usually provide sewer location plans on request – before finalising your conservatory’s design and position.

What could happen if I build over a sewer without the water company’s agreement?

You could later be required to alter or remove the structure at your own cost if the water company needs access, and a standard drainage and water search during conveyancing will typically flag any unresolved build-over issue, which can complicate a future sale or mortgage.

Sources

This guide draws on the following primary sources, current as of 15 September 2026:

• Planning Portal, Building Regulations Part H (drainage and waste disposal) – planningportal.co.uk
• GOV.UK, Building Regulations approved documents – gov.uk/approved-documents
• Legislation.gov.uk, Water Industry Act 1991 – legislation.gov.uk
• Water UK, industry information on sewers and drainage – water.org.uk

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write.

An Article 4 direction is a specific council power that withdraws permitted development rights for a defined area or property — distinct from conservation area status, and worth checking before you design.

This article covers Article 4 directions in England, which remove specific permitted development rights. This is general information – whether one applies to your specific property is something only your local planning authority can confirm.

What an Article 4 direction actually does

Normally, many smaller householder projects – including conservatories that fit within the relevant size and design limits – can be built under permitted development rights, without needing a full planning application. An Article 4 direction is a specific power local planning authorities can use, under Article 4 of the Town and Country Planning (General Permitted Development) Order 2015, to remove some or all of those permitted development rights across a defined area, or in some cases for an individual property. Where a direction applies, work that would normally be permitted development anywhere else instead needs a full planning application, judged on its own merits.

It’s not the same thing as being in a conservation area

These two things are commonly confused because they overlap a lot in practice, but they are legally separate mechanisms. Conservation area status is about a place being formally recognised as having special architectural or historic character worth preserving. An Article 4 direction is a specific, separate legal step a council takes to actually withdraw permitted development rights in response to that character, or for other planning reasons entirely. Councils frequently apply Article 4 directions within or around conservation areas, but a direction isn’t automatic just because you’re in one – and, less commonly, a council can apply a direction in an area that isn’t a conservation area at all, if it has other planning reasons for wanting tighter control over incremental changes.

Why councils use them

Article 4 directions are typically introduced where a council is concerned that the cumulative effect of individually permitted changes – new conservatories, altered windows, removed boundary walls, and similar small-scale works – would gradually erode the character of an area, street, or specific building, even though no single project would otherwise need permission. Rather than trying to stop one project, the direction is aimed at bringing this whole category of change under proper planning oversight going forward.

How a direction usually takes effect

Because withdrawing an existing right can affect people who may have been relying on it, planning practice guidance generally expects most Article 4 directions to be brought in with a notice period – commonly around 12 months from when the direction is confirmed – rather than immediate effect. Immediate-effect directions are possible but are used sparingly, generally reserved for cases where a council judges there’s a real risk of harmful work happening in the meantime, and they carry a greater risk that the council may need to pay compensation to anyone who suffers a genuine loss as a result of the sudden change, for example someone who had firm, costed plans already in place that relied on the previous permitted development rights.

How to check if one applies to your property

• Check your local planning authority’s website – most councils publish a list or map of areas covered by Article 4 directions;
• Contact the council’s planning department directly and ask specifically whether a direction applies to your address or street;
• If you’re buying a property, a Local Land Charges search as part of the standard conveyancing process should flag any Article 4 direction affecting it – make sure your solicitor has checked this specifically if you’re planning any extension work after moving in.

What it means practically for a conservatory

If an Article 4 direction covering extensions applies to your property, a conservatory that would elsewhere in England be perfectly fine as permitted development – meeting all the normal size, height and position limits – will instead need a full planning application before you can build it. This doesn’t mean it will be refused; it means it will be properly assessed against local planning policy rather than being automatically allowed, and you should budget time and a planning application fee for that process rather than assuming the usual permitted development limits apply.

Can you object to an Article 4 direction, or ask for one?

Councils are generally required to consult publicly before confirming most Article 4 directions, which gives residents an opportunity to comment on the proposal before it’s finalised – if you’d be affected by one being introduced in your area, check your council’s consultation process and respond within it rather than only finding out once it’s already confirmed. It’s also possible, in principle, for residents to raise concerns with a council about the cumulative effect of changes in their area and ask it to consider introducing a direction, though whether a council chooses to act on that is entirely a matter for its own planning judgement.

What if you’re not sure whether your project is affected?

If you’re planning a conservatory and there’s any possibility an Article 4 direction covers your property, get written confirmation from the council before you commission detailed designs or commit money to the project – a quick planning enquiry is far cheaper than discovering after the fact that what you assumed was permitted development actually needed a full application. Many councils offer a pre-application advice service for exactly this kind of question, sometimes for a modest fee, which can also flag any other local constraints, such as conservation area or listed building status, at the same time.

FAQs

If my house is in a conservation area, does that mean an Article 4 direction automatically applies to it?

No. Councils frequently apply Article 4 directions within or around conservation areas, but a direction isn’t automatic just because you’re in one – the two are legally separate mechanisms, and a council can in principle apply a direction outside a conservation area too.

How much notice do councils usually give before an Article 4 direction takes effect?

Most directions come in with a notice period of around 12 months from when the direction is confirmed. Immediate-effect directions are possible but used sparingly, and they carry a greater risk that the council may need to pay compensation to anyone who suffers a genuine loss as a result of the sudden change.

Sources

This guide draws on the following primary sources, current as of 15 September 2026:

• Planning Portal, permitted development and Article 4 directions – planningportal.co.uk
• GOV.UK, planning practice guidance on Article 4 directions – gov.uk/guidance/when-is-permission-required
• Legislation.gov.uk, Town and Country Planning (General Permitted Development) Order 2015, Article 4 – legislation.gov.uk

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write.

Permitted development rights for householder extensions apply only to houses, not flats or maisonettes — so a conservatory on a flat needs full planning permission, plus separate consent under the lease.

This article covers permitted development rules in England. Scotland, Wales and Northern Ireland run separate planning systems with their own rules – check the equivalent local guidance if you’re outside England. This is general information, not planning advice for your specific property.

The short answer: permitted development rights for extensions don’t apply to flats

This catches a genuine number of flat and maisonette owners out, because it’s easy to assume that if a conservatory of a certain size is fine without planning permission on a house next door, the same rule applies to your flat. It doesn’t. Permitted development rights for householder extensions – the rules that let many house owners add a conservatory without a full planning application, provided it meets size and design limits – are set out under the Town and Country Planning (General Permitted Development) Order 2015, and they apply specifically to a “dwellinghouse.” Flats and maisonettes are explicitly excluded from this class of permitted development rights, regardless of size, design, or how modest the proposed conservatory is.

Why the distinction exists

The legal reasoning isn’t really about size – it’s about the fact that a flat or maisonette is one unit within a building that’s shared, structurally or otherwise, with other homes. Alterations to one flat can have knock-on effects for the building as a whole and for other residents in a way that’s treated differently in planning law from a standalone house on its own plot. As a result, there is no permitted development route for a conservatory extension to a flat – you need to apply for full planning permission from your local planning authority, and the application will be assessed on its own merits against normal planning policy, without the benefit of an automatic exemption for smaller-scale work.

Does having your own garden change anything?

No. A common assumption is that a ground-floor flat with its own private garden should be treated more like a house for these purposes. It isn’t – what matters legally is whether the property is a flat or maisonette (typically meaning it’s part of a building containing more than one home, however the ownership or garden arrangements are set out), not whether it happens to have direct garden access. If your property is legally a flat, the permitted development exclusion applies regardless of what outside space comes with it.

There’s a second consent hurdle too: your lease

Planning permission is only one part of what you need. Most flats are held on a leasehold basis, and the lease itself very often requires you to get the landlord’s or freeholder’s written consent before making any structural alteration to the property or the building – a requirement that exists entirely separately from planning law. Getting planning permission from the council does not automatically give you permission under your lease, and vice versa. Check your specific lease terms and speak to your freeholder or managing agent early, ideally before you spend money on drawings or a planning application, since a lease restriction can rule out a project that would otherwise be planning-permissible.

What about maisonettes specifically?

A maisonette is generally treated the same way as a flat for these purposes if it doesn’t meet the legal definition of a self-contained “dwellinghouse” – broadly, if it shares any part of the building’s structure with another separate home. Whether a specific property counts as a dwellinghouse or not can occasionally be a genuine grey area depending on exactly how it was built and divided, so if you’re unsure, it’s worth checking directly with your local planning authority or a planning consultant before assuming either way.

What to do instead

• Assume you need full planning permission for a conservatory or extension on a flat or maisonette, rather than checking permitted development limits designed for houses;
• Check your lease for any requirement to get freeholder or landlord consent, separately from planning permission;
• If you’re unsure whether your property legally counts as a dwellinghouse or a flat, ask your local planning authority directly before committing to design work;
• Speak to neighbours or other leaseholders in the building early – alterations to one flat in a shared building are more likely to attract objections than the same work on a standalone house.

What if you’re buying a flat with an existing, unauthorised conservatory?

This is a genuinely common scenario worth being alert to: a previous owner of a flat may have added a conservatory or similar structure without realising permitted development rights didn’t apply, or without realising planning permission was required at all. If you’re buying a flat with an existing conservatory-style structure, your conveyancing solicitor should check whether planning permission was actually obtained, since an unauthorised structure on a flat carries the same enforcement risk as it would anywhere else – and potentially an additional complication if it also breaches the terms of the lease, which is a separate issue from the planning position entirely.

Talk to the freeholder and other leaseholders early

Because a flat sits within a shared building, changes to one unit are often more visible, and more likely to affect other residents, than an equivalent change to a standalone house. Beyond the formal consent requirements, it’s generally worth talking to your freeholder or managing agent, and where relevant your immediate neighbours in the building, before you get too far into design work – not because it’s legally required, but because objections from within the building can complicate both the leasehold consent process and any planning application, and an early, informal conversation can surface concerns while they’re still easy to address.

FAQs

If my ground-floor flat has its own private garden, does that change the permitted development rules?

No. What matters legally is whether the property is a flat or maisonette, not whether it has direct garden access – if your property is legally a flat, the permitted development exclusion applies regardless of what outside space comes with it.

Is planning permission the only consent I need for a conservatory on a flat?

No. Most flats are held on a leasehold basis, and the lease itself very often requires the landlord’s or freeholder’s written consent for structural alterations, separately from planning law. Getting planning permission doesn’t automatically give you permission under your lease, and vice versa.

Sources

This guide draws on the following primary sources, current as of 15 September 2026:

• Planning Portal, permitted development rights for householders – planningportal.co.uk
• Legislation.gov.uk, Town and Country Planning (General Permitted Development) Order 2015 – legislation.gov.uk
• GOV.UK, planning permission guidance – gov.uk/planning-permission-england-wales

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write.