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What Costs Should I Consider When Thinking About Doing A Home Extension?

What Costs Should I Consider When Thinking About Doing A Home Extension?

Do you have a sense of budget costs for the build for new space you are adding to your home but lack clarity on what other costs you may need to consider?

If you are thinking about adding space to your home through an extension to your home, there are multiple facets relative to costs to consider beyond just the cost of the build and allowing for these within your budget plan from the outset will allow you to manage finances through the build process and likely to ensure that the build can be completed to the desired result.

These costs if not factored in, can feel like hidden costs and the last thing you are likely to want is for the budget for the final kitchen being cut because you have not allowed for the cost for the structural engineer to design the steels.

Below we have sought to list some of the costs that you should consider as part of your building project. As each project is unique this list cannot cover all instances and the specifics of your project should be discussed with the experts in your design team.

1. Architectural and Design Fees: You may need to hire an architect or a designer to help you plan and design your home extension. Hiring an architect or a designer to help you plan and design your home extension is an important step. The cost will depend on the size and complexity of the project, as well as the experience of the professional you hire. They will create detailed drawings, plans, and specifications that will be used throughout the building process. They will also help you navigate the planning application process and ensure that your plans comply with all relevant regulations. We have other articles on the site that discuss architect’s fees specifically but to give you a sense, you should budget 10-15% of the build cost for your architect to take the scheme through from start to finish.

2. Planning Application Fee: You will need to pay a fee to the local council when you submit your planning application and for them to assess this. The fees are set nationally and normally in the instance of household applications this is currently just under £250.00.

3. Measured Survey Fees: before an architect can even start to develop a design it is likely that you will need drawings of the existing property, this will include plans, elevations, and potentially a topographical survey. Some smaller architectural teams undertake these themselves, however to ensure accuracy we prefer to engage a third party surveying team to undertake measured surveys with their specialist equipment. The cost will depend on the complexity of the space and size of the area that needs to be surveyed.

4. Structural Engineer Fees: A structural engineer will assess the structural integrity of your home and ensure that your plans are safe. They will design the structural elements of the extension, such as the foundation, walls, and roof. The cost will depend on the complexity of the project , the experience of the engineer and their relative overheads.

5. Client Procured Items: In any building project you may have predefined some aspects that you would like to supply to the builder to help keep costs down; these may include the final sanitaryware choices or large tiles etc.

6. Party Wall Costs: Most home extension projects are likely to require notices to be served on neighbours due to the extent of structural work required under the Party Wall Act etc 1996. Within this bit of legislation, the neighbours have the right to engage their own surveyor at your expense to deal with party wall matters. Costs vary but as a benchmark you should budget circa £3000 to deal with each affected side for party wall matters. Don’t forget if neighbouring properties are flats then these costs can increase as all parties with an interest in the property should be notified.

7. Trial Holes: To establish what is going on in the existing building, consultants may ask for holes to be made or areas exposed so an assessment can be made as to how the building as it stands works. These are normally undertaken by the builder at the instruction of one of the consultants so that assumptions are not made within their design.

8. Moving and Rental Costs: If you are not planning to live in the property whilst you look to do the works, you may need to factor in the cost of moving and renting elsewhere. There is often a trade-off between living in the property and slowing down the build work as opposed to moving out and bearing the additional cost of renting. Build times can increase dramatically if you live in the property and the build team need to work around,

9. Borrowing Costs: With increases in building cost, many people are releasing equity from their homes to finance the build or looking to borrow by other means. The cost of borrowing the money is one that is often neglected but should not be taken lightly. In some instances, you may want to purchase large ticket items using interest free credit cards or HP agreements that allow for zero interest for a set period of time allowing you to spread the cost over a number of years.

10. Contingency: It is a good idea, given the level of investment being ade to set aside a contingency budget in case of any unexpected expenses during the building process. This can include things like additional surveys, changes to the plans, and any unforeseen problems that arise during construction. A contingency budget of 10-20% of the total cost of the project is typical.

As the list above shows, these are just some of the regular costs that you would experience on a typical extension. To manage these, you may wish to hire an architect or project manager, both of whom are well placed to coordinate and establish what is required as soon as initial sketches have been developed.