Home Extension Architects Online Cost  Estimator for Planning Application &  Building Control Submissions

The Architects Cost Tool is intended to help provide a quick quote for our likely charge for Planning Applications and Building Control Submissions. 

Home extensions & Permitted Development

Planning is not always required. Permitted Development gives you a right to develop. The Planning Portal explains which situations Permitted Development is allowed. Bear in mind though that if you sell the house the conveying solicitor will want proof of legality. A Certificate of Lawfulness can be issued by the Local Authority  (LA). (Architects Cost calculator assumes that a planning application is required. It does not work with Permitted Development.)

Local Authority planning fees

To determine what LA Planning Fees could be click here.

Home extension floor area

For Architects Fee Estimator to work it needs to know the scope of the works in square meters. The total new floor area is for example the ground plus first floor for a two storey building, (i.e not the  foot print area.)

Swindon Local Authority Building Control Fees

To ascertain Local Authorities Statutory Building Control Costs use the above floor area and click here.

Home extension building costs

Construction Costs vary greatly. Swindon LA calculate construction costs at roughly £1,200 per m2. However this figure should be treated with great care as rates can  easily quadruple depending on the extent and the quality of the work. 

In order of likelihoods, there are other costs you should be aware of are:

• Increase in house insurance to cover the construction risk etc. Check with the builder's insurance cover to your building etc. and when the Work is close to your neighbours property they are covered by you.

• Diversion or building over  a shared sewer. A Build Over Notice from the Water Authorities will be required.

• When building close or on your  shared neighbour's wall. the Party Wall Act will have to be complied with.

but the above does not cover all eventualities.