Documents for a modular classroom block at an existing school
The permitted development right for school buildings is capped at the lesser of 25 per cent or 100 square metres, so most modular blocks need an application. Playing fields and trees set the programme.
A modular teaching block at an existing school usually needs planning permission, because the permitted development right for school buildings in Part 7 of Schedule 2 to the General Permitted Development Order 2015 is small. Class M allows limited extension or alteration of a school building, with cumulative floorspace capped at the lesser of 25 per cent of the original building's gross floor space or 100 square metres, a height limit of 5 metres, and a standoff from the curtilage boundary. A two or three classroom block will exceed at least one of those limits on most sites.
That matters because these projects run on short programmes tied to the academic year. The application will be determined in eight weeks if it is valid and uncontroversial, and the document list is short, but two items on it can take months to produce: the playing field consultation and any tree work. Both need to start before the drawings are finished.
Permitted development rights available to schools
Read Part 7 Class M itself rather than a summary, because the conditions and the exclusions both matter. The floorspace cap is cumulative, so earlier extensions count, and many schools have used the allowance on a canopy, a store or a previous modular unit.
Where Class M does apply, check the conditions on siting and on the loss of play space before relying on it. And remember that permitted development rights do not displace other consent regimes: building regulations approval, any listed building consent and any tree protection requirements apply regardless.
The practical test is simple. Measure the proposed block, add any extension built since the original building, and compare against 100 square metres and against 25 per cent. If either figure is exceeded, you are making a planning application.
Temporary permission against permanent consent
Schools frequently apply for temporary permission for a modular block, on the basis that the bulge year passes and the building goes. Authorities grant these, and then face an application to extend the period three years later.
Temporary consent earns its place where the need is time-limited and evidenced by roll projections. It is a poor choice where everybody knows the building will stay, because the second application is assessed against the same policies with less goodwill and the building is by then a fait accompli.
Decide which you are asking for and say why. A temporary application should state the end date, the reason the need ends then, and what happens to the site afterwards. A permanent application should address the design and landscape questions properly, which a temporary one can skate over.
Loss of playing field and the statutory consultee
This is the item that decides programme. Where development affects land used as a playing field, or land last used as a playing field within a stated period, Sport England is a statutory consultee under the Development Management Procedure Order 2015.
Three things follow:
- The application cannot be determined without their response, so the eight week clock becomes notional if the consultation is late
- Sport England assesses the proposal against its own published policy exceptions, and a block placed on a pitch will attract an objection unless one of them applies
- Replacement or improved provision is often the route to agreement, which means a sports pitch quality assessment and a commitment to works elsewhere on the site
Site the block off the playing field if the site allows it. Hardstanding, a redundant tarmac area or the footprint of a demolished building are all better starting points, and the submission should explain that alternatives were considered.
Where some pitch area is unavoidably lost, engage Sport England before submitting. A pre-application discussion that settles the replacement provision turns a probable objection into a supportive response.
Daylight and outlook for existing and new classrooms
A new block placed close to an existing teaching wing blocks light to the rooms behind it, and that is a real planning objection rather than a technicality. Classrooms have daylight expectations set by school design guidance, and the ventilation and indoor environment requirements in Building Bulletin 101 interact with the window area.
Model the effect on the existing building as well as the new one. A Daylight and Sunlight Assessment following BRE 209 is the right tool where the separation distance is tight, and the results often move the block by 3 or 4 metres, which costs little at design stage and is impossible later.
Illustrative example. A single storey modular block proposed 6 metres from the south elevation of a 1960s classroom wing. The vertical sky component to the ground floor windows fell below the recommended level for two rooms. Rotating the block through 90 degrees and increasing the separation to 9 metres resolved it without losing any teaching area. Figures are illustrative.
Parking and drop-off where the roll increases
If the block adds pupil places rather than replacing existing accommodation, the roll increases and so does the traffic. Officers and the highway authority will want to know the additional numbers and when they arrive.
What to provide: the existing and proposed roll, the staff numbers, the modal split from the school's travel survey if one exists, the drop-off arrangement, and any changes to the pedestrian route from the gate. A Travel Plan is commonly required by condition for any increase in roll, and offering one with the application is faster than negotiating it afterwards.
Where the block replaces existing teaching space with no roll increase, say so plainly and in the first paragraph of the transport note. Half the objections to school applications assume a roll increase that is not proposed.
Trees on established school grounds
School sites are often the most treed land in a suburb, and the trees are frequently mature, sometimes protected, and usually in the way. A tree survey to BS 5837:2012 identifies the root protection areas, and those areas drive where a modular block can stand and where the crane and delivery vehicles can go.
Modular construction helps here, because the build period is short and the ground disturbance is limited, but the delivery of a module needs a hard route and a lifting position. Plan both with the arboriculturist rather than presenting a layout and asking whether it works. A suitably qualified arboriculturist is what councils expect for this report, and professional review of any draft is strongly advised.
Where a Tree Preservation Order applies, the works need separate consent, and the timescale for that application runs alongside the planning application rather than after it.
Drainage and surface water on a large site
A modular block adds impermeable area, and school sites often already drain to a system at capacity. The lead local flood authority is a statutory consultee on major applications and comments on others.
A Drainage Strategy for a block of this size does not need to be elaborate, but it does need a run-off calculation, a discharge destination, and attenuation sized for the additional area. Permeable paving around the block, a small attenuation crate and a restricted connection are the usual answer.
Check the existing site drainage records first. On older school estates nobody knows where the drains go, and a short CCTV survey at the start is worth more than an assumption at the end.
A short document list for a fast programme
- Planning statement with the roll evidence, the need case and the use of the site explained
- Site and block plans, elevations and a section showing the block against neighbouring buildings
- Tree survey and arboricultural method statement to BS 5837:2012
- Playing field position with Sport England engagement recorded
- Transport note with roll figures, drop-off arrangements and a travel plan
- Drainage strategy with run-off calculations
- Daylight assessment where separation distances are tight
- Biodiversity position, including whether the de minimis exemption from the biodiversity gain condition applies to a block on existing hardstanding
Start the tree survey and the Sport England conversation in week one. Everything else on that list can be produced in parallel once the block position is fixed, and the full set of report types and how they group is on the report index.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Frequently asked questions
Can a school add a classroom block under permitted development?
Only a small one. Class M of Part 7 of Schedule 2 to the GPDO 2015 caps cumulative floorspace at the lesser of 25 per cent of the original building's gross floor space or 100 square metres, with a 5 metre height limit and a boundary standoff. Earlier extensions count towards the cap.
When is Sport England a consultee?
Where development affects land used as a playing field, or land last used as one within the period set out in the Development Management Procedure Order 2015. The application cannot be determined without their response, and their published policy exceptions decide whether an objection follows. Engage before submitting.
Is temporary permission a good idea?
It works where the need is time-limited and evidenced by roll projections, and the application states the end date and what happens to the site afterwards. It is a poor choice where the building will clearly stay, because the renewal application is judged on the same policies with the building already in place.
Does a new block affect daylight to existing classrooms?
It can, and the objection is a real one. Where separation distances are tight, model the effect on existing teaching rooms as well as the new block using the BRE 209 approach. Results often move the building a few metres, which costs nothing at design stage and is impossible after consent.
Does biodiversity net gain apply to a modular block?
Check the de minimis exemption. The biodiversity gain condition regime has thresholds below which it does not apply, and a block placed on existing hardstanding may fall under them. Where it does apply, the statutory metric has to be completed by a competent person and the gain plan approved by the authority.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.