Sheldon Peever Studio

1. Changes to the design.

Modifications to the project scope or design specifications after construction has begun can lead to additional costs. As a result, these changes may require alterations to materials, labour, or project timelines, resulting in increased expenses.

2. Design not working worked out.

Not having a fully worked out design and scope of works can lead to lots of extra work cropping up during the course of construction.

3. Not having a grasp of costs.

Having a limited understanding of the real costs of the whole project before starting on site. Red flag alert! There are likely to be costs crop up that you will not have budgeted for.

4. Smart home systems.

Incorporating integrated smart systems. After all this is a high end luxury product and comes with a price tag to match.

5. Complex design.

Projects that are more complex in terms of design, engineering requirements, or site conditions may require additional resources, expertise, and time to complete, leading to higher costs.

6. Innovative technology.

While technological advancements and innovative construction methods can improve efficiency and reduce long-term costs, they may initially require higher upfront investments, leading to increased project costs.

7. Site Conditions.

Unforeseen site conditions, such as soil instability, environmental contamination, or archaeological discoveries, can necessitate additional work or modifications to the construction plan, resulting in higher costs.

8. Geographical location.

Construction costs can vary significantly depending on the geographic location of the project. As a result, factors such as local labour rates, availability of materials, and regulatory requirements can all impact overall project expenses.

9. Phasing building work.

If you want to do say a loft conversion 1st and then a ground floor extension to enable you to live in during building works that will add some costs. Why? Because the length of time the builder is on site will be longer and their weekly running costs (prelims) will be increased. There may be uplifts in other costs like an Architect or project manager’s fee because of the elongated building programme. Check out our blog on phasing here.

Cost calculator:

If you need some guidance on what the build cost for your home extension or renovation project might be take a look at our cost calculator. Alternatively you can read all about how much building work is costing in 2025 here.