Conservation area consent for windows: the answer is that it does not exist

That leaves the real question, which is whether the work is development needing planning permission — dealt with in full in do you need planning permission to replace windows in a conservation area? — and, if the building is listed, whether it needs listed building consent, which is a genuinely stricter regime. For the whole subject in one place, start with the complete guide to conservation area windows.

This page covers all four nations, because the answer differs by nation in a way almost no published guidance reflects: conservation area consent survives in Wales, Scotland and Northern Ireland, was re-enacted in Wales as recently as November 2024, and in Northern Ireland alone reaches partial demolition.

What conservation area consent actually was

Before October 2013, section 74(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 provided that a building in a conservation area in England or Wales could not be demolished without the consent of the local planning authority or the Secretary of State. That consent was named, in the Act itself, “conservation area consent”.

Read the words that matter: demolished. Not altered, not extended, not re-roofed, not repainted, not reglazed. The section bit on one act only, and windows were not in it.

The reason this is not an accident is visible earlier in the same Act. Section 7 deals with listed buildings, and it is deliberately wider:

no person shall execute or cause to be executed any works for the demolition of a listed building or for its alteration or extension in any manner which would affect its character as a building of special architectural or historic interest, unless the works are authorised under section 8.

Planning (Listed Buildings and Conservation Areas) Act 1990, s.7 — legislation.gov.uk

So Parliament wrote an alteration limb for listed buildings and did not write one for unlisted buildings in conservation areas. That asymmetry is the whole architecture of the system. A listed building’s windows are controlled directly, whatever the works amount to, and unauthorised works are a criminal offence under section 9. An unlisted building’s windows in a conservation area are controlled only through the ordinary planning system, and only if the work is development at all. See windows in a listed building for the other side of that line.

The abolition in England: the citations, correctly

This is worth getting right, because the wrong citations are everywhere — including in professional writing.

ERRA 2013 s.63 and Sch.17; SI 2013/2227 art.2(m); SI 2013/2146 explanatory note

The mechanism had three moving parts, and it is worth seeing all three because the third is the one that makes the new system bite.

One: section 74 was territorially restricted to Wales. Schedule 17 paragraph 12(2) inserted the words “in Wales” into section 74(1), so the consent survived on the statute book but only for Welsh buildings.

Two: a new criminal offence was created for England. Schedule 17 paragraph 6 inserted section 196D into the Town and Country Planning Act 1990 — “Offence of failing to obtain planning permission for demolition of unlisted etc buildings in conservation areas in England”:

It is an offence for a person to carry out or cause or permit to be carried out relevant demolition without the required planning permission.

Town and Country Planning Act 1990, s.196D(1) — legislation.gov.uk

Three: the permitted development right for demolition was switched off. Without this, the new requirement would have been empty, because demolition is generally permitted development. Class B of Part 11 of Schedule 2 to the GPDO 2015 grants permission for “any building operation consisting of the demolition of a building” — but paragraph B.1(b) provides that development is not permitted by Class B if “the demolition is ‘relevant demolition’ for the purposes of section 196D of the Act”. Class C, covering gates, fences and walls, is disapplied on the same basis.

GPDO 2015, Sch.2 Pt.11 Classes B and C — legislation.gov.uk

Note what changed and what did not. The name of the consent changed, the application type changed, and the offence provision moved from the 1990 listed buildings Act to the 1990 planning Act. The scope did not change at all. The Planning Portal’s application type is called, in terms, “planning permission for relevant demolition in a conservation area”, and its guidance says it “should be used for proposals which involve substantial demolition of any unlisted building or structure in a conservation area if permission is required”.

Historic England says the same thing, and says nothing whatever about alteration, windows or fenestration on the page:

Conservation Area Consent was previously needed to demolish unlisted buildings in Conservation Areas. However, since 2013 this is no longer required, but planning permission will be required for ‘relevant demolition’.

Historic England, Conservation Area Consent — historicengland.org.uk, accessed 28 July 2026. We could not find a last-updated date on the page.

Two things about relevant demolition worth knowing anyway

The offence is not a technicality. On summary conviction the maximum is imprisonment for up to 12 months and a fine; on indictment, up to two years. There is a statutory defence in section 196D(4), and it is narrowly drawn: the works must have been urgently necessary in the interests of safety or health, there must have been no practicable alternative, the works must have been the minimum measure necessary, and written notice must have been given to the local planning authority as soon as reasonably practicable.

And the enforcement position is unique. For ordinary unauthorised building operations in England the immunity clock now runs for ten years from substantial completion, or four years where completion was before 25 April 2024. For relevant demolition there is no clock at all:

There is no restriction on when enforcement action may be taken in relation to a breach of planning control in respect of relevant demolition (within the meaning of section 196D).

Town and Country Planning Act 1990, s.171B(2A), inserted 1 October 2013 by ERRA 2013 Sch.17 para.4 (SI 2013/2227 art.2(m)) — legislation.gov.uk

That is a sharp point for anyone buying a house where a building or outbuilding in a conservation area went missing at some unknown date. Compare enforcement, time limits and selling the house, which deals with the ten-year and four-year rules that apply to windows.

The two cubic-metre thresholds, which are constantly conflated

Search for a de minimis figure and you will be told either 115 m³ or 50 m³, often in the same article. Both numbers are real. They come from two different directions doing two different jobs, and confusing them produces wrong answers.

Conservation Areas Direction 2015, para 4 — gov.uk (PDF); Demolition Direction 2021, paras 3 and 4 — gov.uk (PDF)

Neither figure has anything to do with windows. They are here because if you go looking for the boundaries of the conservation area demolition control you will meet both, and because a page that quotes one of them as “the conservation area threshold” is a page that has not read the instruments.

Shimizu: demolition means the whole building

There is one further argument that occasionally surfaces — that stripping the windows out of a building is a partial demolition, and so caught by the demolition control after all. It fails, and it fails on House of Lords authority.

In Shimizu (UK) Ltd v Westminster City Council, decided on 6 February 1997, Lord Hope construed the demolition provisions of the 1990 Act:

the reference to the demolition of a building in a conservation area must be taken to mean the removal of the whole building

Shimizu (UK) Ltd v Westminster City Council [1997] UKHL 3; [1997] 1 WLR 168 — BAILII

Removing components of a building — windows, sashes, a chimney stack, a staircase — is alteration. Demolition, for these purposes, means taking the whole thing away. That is why the Welsh Government’s own guidance can say, without qualification, that “many works which involve the destruction of the fabric of part of a building will not be works of demolition and will not require conservation area consent”.

A related drafting point cuts the same way. Article 3(9) of the GPDO 2015 says that Schedule 2 does not permit development involving the demolition of a building, apart from Part 11 Classes B and C — and then adds that in that paragraph, “‘building’ does not include part of a building”. The Order, like the case law, keeps whole-building demolition in one box and partial works in another.

Wales: it still exists, and it moved on 4 November 2024

This is the point most sources get wrong, because the change is recent and it is Welsh.

Conservation area consent in Wales is no longer granted under section 74 of the 1990 Act. On 4 November 2024, subsections (1), (1A), (2), (3) and (4) of section 74 were omitted by Schedule 13 paragraph 138 to the Historic Environment (Wales) Act 2023, commenced by article 3(d) of SI 2024/860. The consent was re-enacted in Welsh legislation:

• section 161 — a person must not carry out works for the demolition of a building to which the section applies unless the works are authorised under section 162. It applies to any building in a conservation area except a scheduled monument, a listed building, or a building of a description specified in regulations or a direction.
• section 162(3) — “Consent under subsection (1) or (2) is referred to in this Act as conservation area consent.” The name survives.
• section 163 — applies the Part 3 listed building machinery to conservation area consent, reading “character of a listed building” as “character or appearance of the conservation area”.

Historic Environment (Wales) Act 2023, s.161, s.162, s.163; in force 4 November 2024 by SI 2024/860 art.3

The scope is still demolition only. Welsh Government guidance is explicit on both halves of the point. TAN 24, chapter 6, states at paragraph 6.10 that conservation area consent “is required for the demolition of an unlisted building in a conservation area”, and that “the courts have ruled that demolition amounts to pulling down a building so that it is destroyed completely or at least to a very significant extent”. Paragraph 6.11 records that the 2024 Regulations disapply the consent for, among other things, “the demolition of a building with a total cubic content not exceeding 115 cubic metres”. Planning Policy Wales edition 12 puts the alteration point beyond argument at paragraph 6.1.17: conservation area designation “introduces control over the total or substantial demolition of unlisted buildings within these areas, but partial demolition does not require conservation area consent”.

Welsh Government, TAN 24: The Historic Environment (March 2026), paras 6.10–6.12; Planning Policy Wales edition 12, para 6.1.17. PPW 12 predates the 2023 Act’s commencement and still cites the 1990 Act; where the two diverge, TAN 24 is the current text.

Two things Welsh readers should not be told. It was not the Planning (Wales) Act 2015 or the Historic Environment (Wales) Act 2016 that moved conservation area consent — we found no provision of either Act touching it, and the 2023 Act is the operative instrument. And any page still telling you that Welsh conservation area consent is granted under section 74 of the 1990 Act is out of date by more than eighteen months.

Scotland: unchanged, and still not about windows

Section 66(1) of the Planning (Listed Buildings and Conservation Areas) (Scotland) Act 1997:

A building in a conservation area shall not be demolished without the consent of the appropriate authority (in this Act referred to as “conservation area consent”).

P(LBCA)(S)A 1997, s.66 — legislation.gov.uk. Procedure: the Planning (Listed Building Consent and Conservation Area Consent Procedure) (Scotland) Regulations 2015, SSI 2015/243.

The only substantive change since 1997 came on 1 October 2015, when section 66(2) was substituted by the Historic Environment Scotland Act 2014 to name the appropriate authority as the planning authority or the Scottish Ministers. That is a change of decision-maker, not of scope. There is no alteration limb, and replacing the windows of an unlisted building in a Scottish conservation area is not a conservation area consent matter.

What it is in Scotland is a Class 7A permitted development question with a prior notification step for front and road-facing elevations — a materially different process from England’s, and covered in conservation area window rules in Scotland, Wales and Northern Ireland.

Northern Ireland: the one place partial demolition counts

Section 105(2) of the Planning Act (Northern Ireland) 2011 requires conservation area consent for the demolition of a building in a conservation area, other than a listed building or a building in a specified class. So far, so familiar. Then section 105(8) does something no other UK jurisdiction does:

For the purposes of this section, any reference to demolition, in relation to a building to which this section applies, includes a reference to any structural alteration of that building where the alteration consists of demolishing part of the building.

Planning Act (Northern Ireland) 2011, s.105 — legislation.gov.uk. In operation 13 February 2015 for specified purposes and 1 April 2015 otherwise, by SR 2015/49; see also the Planning (Conservation Areas) (Demolition) Regulations (Northern Ireland) 2015, SR 2015/107.

Read the two limbs. The alteration must be structural, and it must consist of demolishing part of the building. Taking a sash out of an existing opening and putting another one back in is neither. But enlarging an opening, blocking one up, or removing a bay or an oriel takes out masonry, and that is a materially different proposition in Northern Ireland from what it would be in England, Wales or Scotland.

The four nations at a glance

So what do you actually need for your windows?

Having cleared the wrong question out of the way, here is the right sequence. Each of these is a separate regime with a separate answer, and a “no” to one says nothing about the others — see the glossary if any of the terms are unfamiliar.

1. Is the work development at all? If nothing about the external appearance of the building materially changes — the clearest case being a new sealed unit in the existing sash, with sightlines, glazing bars and profiles unchanged — then it is not development under section 55(2)(a) of the 1990 Act and no permission is needed. This is the single most valuable distinction on this site: see double glazing in a conservation area.
2. If it is development, is it permitted development? For a house in England, replacing windows is normally within Class A of Part 1 of Schedule 2 to the GPDO 2015, and conservation area designation on its own does not withdraw that right. Details, with the text of paragraph A.2, in do you need planning permission to replace windows in a conservation area?.
3. Has an Article 4 direction withdrawn the right? This is the question that actually decides most cases, and it is address-specific. See Article 4 directions and your windows.
4. Is it a house or a flat? Part 1 permitted development rights belong to dwellinghouses, and the GPDO’s definition excludes flats and maisonettes. See windows in a flat or maisonette.
5. Is the building listed? If so, listed building consent is a separate and stricter question, engaged by alteration affecting character whether or not the work is development, and unauthorised works are a criminal offence. See windows in a listed building.
6. Does it meet building regulations? Replacing a window is work to a controlled fitting, and a FENSA or CERTASS certificate answers this question and nothing else. See building regulations for replacement windows.

If the answer to steps 2, 3 or 4 means you have to apply, the application is an ordinary householder planning application, not a conservation area consent application — and what the officer will actually look at is covered in applying for windows: drawings, fees and what officers look at.

If someone tells you to apply for conservation area consent

It still happens, including from councils whose web pages have not been rewritten since 2013. Three practical responses.

Ask which application type they mean. In England there is no conservation area consent form and no fee for one. If the authority means a householder application for the windows, say so and apply for that. If the authority genuinely means the demolition consent type, then the proposal has been misunderstood, because windows are not demolition.

Put the citation in the email. Naming ERRA 2013 Schedule 17, SI 2013/2227 article 2(m) and section 196D of the 1990 Act tends to end the discussion quickly, and it costs you nothing.

Do not treat the correction as an answer to the real question. Conservation area consent being irrelevant does not mean your windows need no permission. It means the permission question is the ordinary planning one, and in a conservation area with an Article 4 direction the answer to that is frequently yes. Getting the regime right is the beginning of the analysis, not the end of it.

Every source cited on this page is listed, with the date we checked it, on the sources page.