HOUSE EXTENSIONS

HOUSE EXTENSIONS WITH ACA

Do you need more space for your growing family? Perhaps your home is in need of a makeover? Well, Allan Corfield Architects can help. It’s easier and more cost effective than you may think to extend or convert your garage or attic into a more habitable space. Now might be just the right time to consider a house extension.

ACA have completed numerous house extensions, mainly in the Central belt of Scotland – from Fife to Perth & Kinross, and from Edinburgh to the Scottish Borders. With the Government’s Permitted Development rights, you may not need Full Planning Permission for a house extension – this route makes it less expensive and time-consuming than you may think!

Over the last 6 years ACA have tailored the required house extension service to help the average homeowner get the necessary approvals in place – as well as assistance in appointing a trusted local contractor.

When ACA provide a Fee Proposal for a house extension, we will split the required services up into logical stages. These have a fixed cost and an advised timescale. The RIBA suggest that an average fee for this type of project would equate to between 9-12% of the overall Construction Cost.

At ACA, we believe our clients should know all of the main facts and costs before committing to a project, so we work on a fixed cost rather than a percentage – that way our fee isn’t determined by how expensive your build is!

STAGE 1

SURVEY & EXISTING DRAWINGS

STAGE 2

INITIAL DESIGNS

STAGE 3

PLANNING/CERTIFICATE OF LAWFULNESS

STAGE 4

BUILDING WARRANT APPLICATION

STAGE 5

ON SITE SUPERVISION

STAGE 1 – SURVEY & EXISTING DRAWINGS

Complete a basic measured survey of your existing home
Draw-up your existing home in our 3D drawing package
Provide Plan, Section & Elevations of your current home and garden

Estimated time – 1 week to complete drawings

STAGE 2 – INITIAL DESIGNS

Meet with you to prepare a Project Brief (completed at initial meeting)
Complete a Project Programme, estimating how long the project should take
Prepare 2 or 3 design options in our 3D drawing package
Prepare our BIMx model, so you can walk around your home on your PC, TV or iPad
Complete a final option for your approval

Estimated time – 2 weeks to complete drawings

STAGE 3 – PLANNING OR CERTIFICATE OF LAWFULNESS APPLICATION

Add relevant Planning information to drawings
Complete computer visualisations to aid planning application process
Complete online planning application submission
Deal with any planning queries during the process

Estimated time – 2 weeks to complete drawings

Note – Full Planning Approval process will take a minimum of 8 weeks, Certificate of Lawfulness application (under permitted development) will take a minimum of 4 weeks.

STAGE 4 – BUILDING WARRANT APPLICATION

Obtain Structural Engineer quotes for the design service
Upgrade Planning drawings and add relevant construction information to layouts
Prepare basic construction details
Prepare warrant specification
Complete U-value calculations
Liaise with Structural Engineer and add their design information onto the architectural drawings
Obtain local builders’ estimates for the works
Lodge the Building Warrant application via the online portal (4-6 week review period)
Deal with any warrant queries
Help appoint a trusted local builder for your project

Estimated time – 3/4 weeks to complete drawings

If required ACA can also assist with on-site supervision, and checking of the local contractor’s work. However, we would hope that the contractor chosen would not need any assistance during the house extension construction – due to the quality of the information provided and the suitability of the contractor.

STAGE 5 – ON SITE SUPERVISION

Regular site visits to check on work and provide any assistance to the contractor
Provide Completion Certificate visit and certification via the local Council

Estimated time – 1 visit per calendar month (dependant on requirements)

ADDITIONAL INFO

Pre-application Planning Enquiry

If your project is contentious or doesn’t comply with Permitted Development it may be worthwhile getting pre-application planning advice. Some planning departments will discuss the proposals over the phone, but due to workload most of the Councils now require a formal application. A Pre-Application enquiry is a cost effective route which will give you a formal response from the planning team. The process usually takes 21 days and shouldn’t cost any more than £160.

Structural Engineer Services

You will need an Engineer on most house extension or conversion projects for the Building Warrant Stage. The engineer will access the existing home and ground condition, before designing the foundations and the super-structure for the house extension. They will also provide any calculations required in order to satisfy the building warrant application. A local Structural Engineer’s costs for a single storey house extension should be approx. £600 to £800 (ex VAT).

GENERIC FEE PROPOSAL –

To give you an indication of how the costs are made up on an average house extension project, we have based this example of a single storey sun room extension with internal alterations. Budget approx £40,000 ex VAT:

Stage 1:	Stage 1: Existing Drawings	£540 (ex VAT) or 15% of total fee
Stage 2:	Initial Designs	£900 (ex VAT) or 25% of total fee
Stage 3:	Planning Application	£720 (ex VAT) or 20% of total fee
Stage 4:	Building Warrant	£1,260 (ex VAT) or 35% of total fee
Stage 5:	On site Supervision	£150 per visit
Total fee	Total fee £3,600 (ex VAT)