Building Regulations Exemptions Schedule 2 Guide

Q: My customer wants to use their exempt garden building as a home office — does that change anything?

An occasional home office use (a desk in a garden building) typically doesn't change the Class 6 exemption status, as it is not "sleeping accommodation" and not a material change of use. However, if the customer intends to use it for a business that requires planning consent, or if people other than the household use it as a place of work, different considerations may apply (including the Workplace Regulations). For purely personal use as a home office, the Schedule 2 exemption generally holds.

Q: Can I install a toilet in an exempt building?

Yes, but the drainage and water supply are separate matters. The building structure remains exempt under Class 6, but the connection to drainage must comply with Part H (drains), and if the cold or hot water supply is shared with, or located inside, the dwelling then requirements G1 and G3(2)/(3) apply to the exempt building too. You may need to submit a building notice just for the drainage work, even if the building itself is exempt.

Q: Does an exempt building still need planning permission?

These are separate systems. A building can be exempt from Building Regulations but still require planning permission. Garden buildings are typically permitted development for planning (subject to conditions), but always check the specific planning rules for the location — especially in Conservation Areas or where Article 4 Directions remove permitted development rights.

Summary

Building Regulations apply to the erection, extension, and material alteration of buildings in England and Wales. However, Schedule 2 of the Building Regulations 2010 lists categories of buildings and works that are exempt — meaning no full plans or building notice application is required and no Building Control approval is needed.

This is different from planning permission. A building can be permitted development (no planning required) but still require Building Regulations approval — for example, a large garage. Conversely, some works require planning but are exempt from Building Regulations. The two systems are independent and must be checked separately.

For tradespeople, knowing the limits of Schedule 2 prevents unnecessary delays (making applications for exempt work) and protects against enforcement action (assuming exemption applies when it does not).

Key Facts

Schedule 2 categories (the actual class numbering) — Class 1 (buildings controlled under other legislation, e.g. explosives, nuclear installations, scheduled monuments), Class 2 (buildings not frequented by people), Class 3 (greenhouses and agricultural buildings), Class 4 (temporary buildings), Class 5 (ancillary buildings — site huts, construction/civil engineering site buildings, mine and quarry buildings), Class 6 (small detached buildings), Class 7 (extensions). Note that many trade sources number these incorrectly
Class 6 — small detached buildings — a detached single-storey building with a floor area ≤30m², containing no sleeping accommodation, and either (i) no point of which is less than 1m from the boundary of its curtilage, or (ii) constructed substantially of non-combustible material. Separately, any detached building with a floor area ≤15m² containing no sleeping accommodation is exempt regardless of boundary distance
Combustibility condition — a Class 6 building between 15m² and 30m² sited within 1m of a boundary must be constructed substantially of non-combustible material
Class 7 — extensions — the extension of a building by the addition at ground level of a conservatory, porch, covered yard, covered way, or a carport open on at least two sides, where the floor area of the extension does not exceed 30m². Where a conservatory or porch is wholly or partly glazed, the glazing must satisfy the requirements of Part K (K4, K5.1–K5.4) — this is a safety glazing condition, not a requirement that the walls be translucent
Class 4 — temporary buildings — a building not intended to remain where it is erected for more than 28 days
Water supply catch (regulation 9) — the exemptions in Class 6 and Class 7 do not disapply requirements G1 (cold water supply) and G3(2) and (3) (hot water systems) where the building or extension receives a cold or hot water supply shared with, or located inside, a dwelling. A garden room with a shared hot water feed is not fully exempt
The "50% translucent roof" test — this comes from the Part L definition of a conservatory (thermally separated, and largely glazed roof and walls), not from Schedule 2. Building control bodies commonly apply both tests, so plan for both
Material change of use — converting a building to a different use (e.g., garage to habitable room) is almost never exempt; new use triggers full compliance with applicable Parts
Electrical work — not covered by Schedule 2 structure exemptions; electrical work has its own notifiable/exempt categories under Part P (minor works by householder; major works by registered competent persons)
Wales — similar framework but some differences in details; the Welsh regulations govern
Partial exemption — some work may be exempt from specific Parts but not others; e.g., a single-storey extension may not need structural calculations (Part A) assessed if small enough, but Part L energy efficiency still applies

Quick Reference Table

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Work Type	Exempt from Building Regs?	Key Conditions
Detached building ≤15m²	Yes (Class 6)	No sleeping accommodation
Detached single-storey building 15–30m²	Yes (Class 6)	≥1m from boundary or substantially non-combustible; no sleeping accommodation
Conservatory ≤30m²	Yes (Class 7)	Ground level; glazing satisfies Part K; in practice also thermally separated with a largely glazed roof
Porch ≤30m²	Yes (Class 7)	Ground level; glazing satisfies Part K; existing external door retained
Carport ≤30m²	Yes (Class 7)	Open on at least two sides; ground level
Covered yard or covered way ≤30m²	Yes (Class 7)	Ground level
Greenhouse (domestic use)	Yes (Class 3)	Not used for retailing, packing or exhibiting
Temporary building (<28 days in place)	Yes (Class 4)	Must genuinely be removed within 28 days
Fence, gate, garden wall	Generally yes	Max 2m high (1m adj highway) — planning rule; no regs requirement unless structural/retaining
Replacement windows (same-for-same)	Notifiable but not full plans	Must use FENSA/Certass registered installer, OR Building Notice
Extension (single-storey)	No — notifiable	Submit building notice or full plans; energy/structural standards apply
Loft conversion (habitable room)	No — notifiable	Part A structure, Part B fire, Part L energy, Part F ventilation, Part P electrical all apply
Garage to habitable room conversion	No — notifiable	Material change of use; Part L, Part B, Part F, Part P all triggered

Detailed Guidance

Class 6 — Small Detached Buildings in Detail

The most commonly misapplied exemption. (It is also the most commonly misnumbered — a lot of trade guidance calls it Class 5, which is actually ancillary buildings such as site huts.) The conditions:

Floor area ≤15m² (no boundary restriction): The building can be sited at any distance from the boundary. Size limit only. No sleeping accommodation permitted (bedroom/holiday let removes exemption).

Floor area 15–30m², single storey: The building must be sited at least 1m from any boundary of its curtilage OR must be constructed substantially of non-combustible materials.

Non-combustible construction means walls and roof of brick, block, concrete, metal, or other non-combustible materials — a standard timber-frame with timber cladding would NOT meet this unless the cladding and structure are non-combustible (e.g., a steel portal frame with concrete board cladding).

What is excluded:

Any building containing sleeping accommodation — the 1m/30m² exemption does not apply; if anyone sleeps there, it's habitable space and requires full Building Control
Any building connected to mains drainage — drainage connection triggers Part H (drainage) requirements; this does not remove the structural exemption but drainage work is separate
Any building with gas or electrical installation — the electrical work has its own competent person route (Part P); the gas work is always Gas Safe-notifiable
Any Class 6 building receiving a cold or hot water supply shared with, or located inside, a dwelling — requirements G1 and G3(2) and (3) still apply to it, even though the building itself is otherwise exempt. This is the trap on garden rooms plumbed off the house

Conservatory Exemption Conditions

The Part L exemption for conservatories is discussed in detail in conservatory planning, but the Schedule 2 Building Regulations exemption is different. Strictly, Schedule 2 Class 7 sets only three conditions: the addition is at ground level, the floor area does not exceed 30m², and where the conservatory is wholly or partly glazed, the glazing satisfies Part K (safety glazing in critical locations).

In practice, building control bodies also apply the Part L definition of a conservatory, so plan for all of the following:

Floor area ≤30m² — if larger, full Building Regulations apply including Part A structure, Part L energy, Part C moisture
Separated from dwelling — there must be an external-quality door or wall between the conservatory and the main house, and the existing heating system must not be extended into it. If the wall is removed to open the conservatory directly into the house, the exemption is lost
Largely glazed — the Part L definition requires at least 75% of the roof and at least 50% of the walls to be glazed or translucent. An all-tile solid roof makes it an extension, not a conservatory
Ground level — not an upper-storey conservatory
Safety glazing to Part K in doors, side panels and low-level glazing
Not used as sleeping accommodation

When the exemption applies, no Building Control notification, no full plans, and no inspector visits are required (unless there are associated structural works like removing a wall between house and conservatory — which requires Building Control for the structural alteration).

Permitted Development vs Building Regulations: Getting the Balance Right

These are the most commonly confused concepts:

Example 1: Large garage (60m²)

Planning: Permitted development if within the limits (up to 50% of garden covered, etc.) — likely yes
Building Regs: Not exempt (over 30m²) — must submit building notice or full plans Result: Can build without planning but needs Building Regulations

Example 2: Rear extension (30m², single-storey)

Planning: Permitted development (under 3m for attached; 4m for detached) — yes
Building Regs: Not exempt — must notify Building Control; Part A (structure), Part L (energy), Part C (damp), Part B (fire) all apply Result: Can build without planning but needs Building Regulations

Example 3: 12m² garden shed

Planning: Permitted development — yes
Building Regs: Exempt (Schedule 2, Class 6) — yes Result: Neither planning nor Building Regs required

When Exemption Does Not Apply (Common Mistakes)

Converting a garage to a room — even if the garage was originally exempt, changing its use to habitable accommodation is a material change of use that triggers full Building Regulations compliance for the converted space
Electrical work in an exempt building — the building being Schedule 2 exempt does not exempt the electrical installation from Part P; competent person self-certification or Building Control notification still required for notifiable electrical work
Drainage connection — connecting any building to public sewer or private drainage system is not exempt; Part H drainage regulations apply
Water supply shared with the dwelling — a Class 6 or Class 7 building that takes a cold or hot water supply shared with, or located inside, a dwelling must still meet G1 and G3(2)/(3). The structural exemption does not carry the plumbing with it
Building in flood risk zone — some exemptions are more limited in high-risk flood zones; check Flood Risk Zones 2 and 3
Temporary buildings that stay put — the Class 4 exemption only covers a building not intended to remain where it is erected for more than 28 days. Leave it there longer, or install what was described as temporary on a permanent basis, and the exemption is lost

Frequently Asked Questions

My customer wants to use their exempt garden building as a home office — does that change anything?