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Planning and building standards

Extension checklist

Use this list to check your plans before you submit your building warrant for an extension. It could help speed up the process by making sure you have everything you need.

The checklist includes common points raised by our surveyors when assessing extension applications. It's not complete list as projects can vary.

Before you start

You'll need:

  • completed building warrant application form
  • form should include applicant's name, address, phone number and email address
  • if using an agent such as an architect, the form should also include agent's name, address, phone number and email address
  • correct fees
  • appropriate plans and specifications

General checklist

General checklist
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number
Provide 2 copies of the following plans or drawings: 
Block or site plan at a scale of 1:200 or 1:500. 
Location plan at a scale of 1:1250. This should be outlined in red ink. 
Elevations and floor plans of the building as existing at a scale of 1:50 or 1:100. 
Elevations and floor plans of the building as proposed at a scale of 1:50 or 1:100. We may need a larger scale of the proposed floor plan of 1:20 if the work is complex. Plans should show proposed works coloured as per the Procedural Regulations. 
Sectional elevations through the proposed works at a scale of 1:50. We may need larger scale sections at a scale of 1:20 to show specific construction details. 
Full dimension plans. Include all critical dimensions and show use of rooms. 

A full construction specification.

This be clear notes added to the plans or a separate specification sheet to read with the plans. Generic specifications are not suitable. All specification should be specific to the actual works applied for.

If you apply online, submit a separate specification sheet we can read with the submitted plans. All plans must have a title block with applicants name, site address, a description of the plan.  Include the scale and unique reference number.

 
Confirm age of the property to decide which category the U values should comply with. This refers clause 6.2.9 of the Domestic Handbook 2010. 

General points for simple extension 

General points for a simple extension
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number
Foundations should be same depth as existing foundations or 450mm deep - whichever is greatest. 
Specify size of foundations. 
Provide a full dimensional foundation layout plan. 
Specify below ground wall construction. 

Cavity below ground level requires to be filled up to ground level.

 

Specify solumn construction.

 

Indicate DPM to solumn.

 

DPC to walls need to be minimum 150mm above ground level.

 

Provide section plan through substructure (if required).

 

Provide annotated drainage layouts (existing and proposed) showing foul and surface water drains. Show connection of new drainage to a suitable existing drainage system.

 

Suspended ground floor/mid floor (timber or concrete).

 

Specify floor construction.

 

Indicate and specify sub floor ventilation on floor plan and elevation.

 

150mm clear air space required between solumn and underside of floor joists/floor slab.

 

Provide floor joist layout plan including all joist sizes, joist centres and dwanging.

Specify depth of floor slab.

 

Specify support to floor joists/suspended floor slab.

 

Show and specify insulation to ground floor and provide a u value calculation.

 

Specify size and type of floor boards.

 

If chipboard flooring used, moisture resistant flooring is required to kitchen and bathroom areas.

 

Solid ground floor.

 

Specify ground floor construction.

 

Show and specify damp proof membrane to floor.

 

Show and specify insulation to floor and provide a u value calculation.

 

 External walls checklist

External walls checklist 
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number

Specify external wall construction.

 

If block work used, specify density of blocks.

 

Specify wall ties.

 

Specify method of tying new walls to existing.

 

Specify insulation to external wall and provide a u value calculation.

 

Specify lintels to openings.

 

Show fire protection to walls within 1m of any boundary.

 

Specify cills to openings, including DPC.

 

Specify cavity closers, including DPC.

  

Show and specify movement joints to walls, if needed.

 

 Timber frame external walls additional checklist

Timber frame external walls additional checklist
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number
Provide timber panel drawings. 
Provide nailing schedule. 

Specify anchor straps to kit and indicate on plans.

 

Show and specify moisture barrier and vapour membrane.

 

Specify cavity barriers and indicate on plans.

 

Specify cavity ventilation.

 

Show fire protection to walls within 1m of any boundary.

 

Roof checklist 

Roof checklist
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number

Provide a roof member layout plan.

 

If hand cut trusses to be formed on site, specify all roof timber sizes. The design may need to be accompanied by design calculations.

 

If pre manufactured trusses to be used, provide a roof truss design certificate.

 

Specify under felt.

 

Specify baton and counter baton sizes.

 

Specify roof covering.

 

Specify tie down straps, truss clips, lateral restraints.

 

Specify valley gutters (if applicable).

 

Specify ventilation to roof voids.

 

Specify roof insulation and provide a u value calculation.

 

 Electrical checklist

Electrical checklist
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number

All electrical works to be to BS7671 : 2008 (17th edition of IEE Regulations).

 

Electrics to be installed and/or tested by a SELECT or NICEIC approved electrician. An electrical certificate is needed before completion is approved.

 

Show all lighting points and sockets on plans.

 

Specify height of sockets and light switches on plans.

 

Show and specify all mechanical ventilation on plans.

 

Show all mechanical vent terminals on elevation plans.

 

Extend smoke detection/heat detection system to extension where needed and show on plans.

 

 Gas and boiler checklist

Gas and boiler checklist
Mark the plan or drawing with the following and submit with your applicationPlan or drawing number

A GasSafe registered engineer needs to undertake any proposed boiler installations.

 

Shown a carbon monoxide detector on the plans.

 

 Plumbing and draining checklist

Plumbing and draining checklist
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number

Show all existing and proposed underground drainage.

 

Show all proposed internal pipework.

 

All wash hand basins and WCs need to be fitted with water saving devices.

 

Glazing checklist 

Glazing checklist
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number

Specify u value to glazing.

 

Specify locks to vulnerable doors and windows. Refer to 'Secure by Design' standards.

 

Specify any low level glazing (under 800mm from floor). Low level glazing to be toughened.

 

Show and specify escape windows where needed.

 

Show opening configuration for all windows and doors.

 

 Stairs and landing checklist

Stairs and landing checklist
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number

Specify all internal and external stairs and landings.

 

 General checklist 2

General checklist 2
Mark the plan or drawing with the following and submit with your applicationCheck or give plan or drawing number

Sound proofing.
Depending on the layout, apartments require to be individually soundproofed.

 

Party walls.
If needed, specify any party walls.

 

Add this note to the plans:
'The Relevant Person is responsible for ensuring all works are carried out in accordance with The Building (Scotland) Act 2003, as amended, and The Building (Scotland) Regulations 2004, as amended.'

 

The building warrant is subject to a Construction Compliance & Notification Plan (CCNP). This will be issued when the warrant is approved. The CCNP needs you to contact us at all stages listed on the CCNP when ready for inspection.

 

Related information

pdf icon Download extension checklist [37kb]

Apply for a building warrant

Building warrant fees

Loft checklist


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