What Will the Build Cost?

If you are planning to have your design built to sell straight away, this may bring you a much greater return than selling the land with Planning Permission alone. However, you will need to have the capital to fund this and there is the risk of a fluctuating housing market whilst you take the time to build it. We suggest you talk to your local estate agent to provide you with a clear idea of potential value. Alternatively, you may not wish to sell the new property immediately, as it may be for yourself or a relative, or you may wish to rent it out. Again, it would be wise to speak to an estate agent to get a clearer idea of rental value and long-term potential.

Should you decide to build the house, below is a rough guide to how much this will cost:

• Below is a rough guide to how much the building cost of an extension may be, based on the internal floor area on flat ground with no obvious problems:

  • £1500 per sq m or £140 per sq ft – Basic structure completed by the builder, interior work finished by yourself

  • £2100 per sq m or £196 per sq ft -Basic structure with simple internal, decorated finishes and electrics/heating completed by the builder

  • £2350 per sq m or £219 per sq ft – More complex structure with intermediate level internal finishes and decoration completed by the builder

  • £2900 per sq m or £270 per sq ft – More complex structure with luxury internal finishes and decoration completed by the builder

  Both the pandemic and Brexit have had a significant impact on material and labour costs, making it harder to predict the cost of a build.

  While the rough guide above provides an indication of costs, we highly recommend a getting budget estimate produced by a specialist for any agreed scheme. The budget estimate will provide a more accurate reflection of the build cost at that time, based on current pricing information, and is generally considered to be within 10% of the likely final cost. Although please note that there will be some caveats, allowances, and exclusions from it.

There will also be fees on top of the build cost. These will include the following:

• Architect’s fees for Building Regulations drawings - These will vary depending on the size and complexity of the design of your new house. 3HW’s fees for all the drawings and documentation for Building Regulations for this type of project start at £3,000 +VAT. Our service includes all the drawings and information needed to get Building Regulations Approval and for the builder to construct the house, with no hidden extras.

• Local Authority fees for submission of Building Regulation plans - There is a fee payable to the Local Authority on submission of your designs to Building Control. Current Cornwall Council Building Control charges for a single dwelling start at £1220 including VAT.

• SAP Calculation - These are calculations which work out the potential heat loss from your new building, and are necessary for providing the Energy Performance Certificate - which every new build requires. This will cost approximately £240 +VAT.

• Air Test - The price will vary depending on which company provides the test but will cost in the region of £300 including VAT.

• Additional Fees - There may be some additional fees depending on the individual circumstances of your project. For instance, you may need to use a structural engineer, you may need further site investigations due to the results of your mining report, or you may need a full site investigation to determine ground conditions. Your architect will advise you on what you may need and approximate costs.

3HW’s fees for all the drawings and documentation for Building Regulations for this type of project start at £3,000 +VAT. Please contact us for more details