Building an Extension – Professionals You Need In 10 Easy Steps: Design changes to meet the budget

Meet the budget

Step 4 – Design Update

As you will have read in the previous stage The Cost Plan, we now have a good idea of how the build cost relates to your available budget, so what can we do now? we need to meet the budget!

Meet the budget

This stage will start off with either reducing the works to meet the budget or if you are in the situation where you have more budget than the build cost shown in the cost plan it could be worth looking at adding some more luxurious fixtures or fittings or upgrading items like windows to a more efficient energy rating so you get some long term benefit from the upgrade

A word of caution

However, a word of caution, you must be mindful of your long-term plans for the property, going too luxurious with fixtures and fittings may not pay dividends when you come to sell your property in the future.

Also, some finishes may not be to your future purchasers’ taste and not add any benefit at all, sometimes the complete opposite affect is achieved.

If selling in the future is your preference there is no substitute for square footage or square metres, again be mindful that scale and proportion is key, so the property doesn’t look over developed and you lose too much of your outdoor space.

To maximise the value of the work you are having carried out additional square metres are king

Calculate the value of the works

A simple exercise to carry out is to look at larger properties that have sold in your road, the online estate agencies normally publish a floor plan with the overall metre squared of the property.

It is then a case of doing a simple calculation of sale price divided by metres squared, this will then give an indication of the expected increase per metre squared of floor space you add to your property.

Don’t forget to deduct the cost of creating this extra floor space, the value left over is your potential profit, this is why it is so important to meet the budget before its too late

This can be further reinforced by inviting a local estate agent to appraise the property and proposed works to get an additional idea of what financial benefit the work will create.

Lots to take into consideration!

We will assume that the build cost from the cost plan means that we need to work on cutting our cloth to get within budget, this can be achieved but will depend on how far away the build cost is from your budget.

Minor changes

Floor coverings – there are a vast amount of products on the market that could suit your project and meet the budget, remember if you have say 150 square metres of flooring in your project by reducing the cost per square metre by £10 will save £1500.


If you are planning to have a kitchen and utility room, you can save some money in the short term by only fitting out the kitchen and deferring the utility to a later date. Just make sure that there are no plans for the kitchen units to be discontinued in the near future or matching these at a later date could cause an issue


The variance for bathroom fittings is vast, from £65 for a basic close coupled toilet pan & cistern or £1000+ for a Villeroy & Boch, as you would expect the cost goes up to tens of thousands for more.

Bespoke joinery

Where possible try and use stock door sizes rather than bespoke sizes as the cost escalates quickly.

Get the right look

Overall our advise is to be clear of what look you want to achieve and research as much as you can, you will be surprised what can be save by a bit of haggling to meet the budget

A great source of  inspiration are sites like Houzz

Next let’s look at Step 5 – Schedule of Works

Tagged on: