Prices

Single Storey Extension

From £595.00

Two Storey Extension

From £695.00

Loft Conversion

From £695.00

Garage Conversion

From £395.00

Garden/Sun Room

From £595.00


The above prices include a site-survey, detailed design plans and specification, and a full-submission service to the Local Authority.

We offer a multi-plan discount where work entails more than one extension.

Structural calculations, heat loss, SAP, U-value and water useage calculations can be provided.  These vary in price depending on the specific requirements of the project.

In addition to the above costs, you will be expected to pay approximately £35 for the location plans of your property.  These additional plans are required by Planning and/or Building Control when your application is submitted.

Where planning permission is required, the Local Authority will charge a fee for obtaining Household Planning Consent.  As at January 2018 the fee for this is £206.  Where Building Regulation approval is required, a separate fee is payable, this varies according to the required work.

What would I expect to pay for a design and submission service, for a single-storey extension of 15m2 in Sheffield with no additional calculations?


  • £595 for a site-survey and plan design (Attollo Building Design)
  • £35 for Ordnance Survey location plans
  • £206 for household planning consent (payable to Planning within Local Authority)
  • £180 for plan assessment fee (payable to Building Control within Local Authority)
  • £336 for inspection fee once building work commences  (payable to Building Control within Local Authority)

Total £1352

[This price is correct as at January 2018)



It is recommended that quotes for your proposed project are obtained from 3 different building companies.  As a general rule of thumb, the average build cost is approximately £1500 per square metre of extended floor space.