35 Ways to Save Money on a House Extension

A home extension is so exciting: you’re about to create a space that’s perfectly tailored to you and your family, and put your design stamp on it. But there’s no denying they’re financially challenging.

While we would never advise you look to cut costs on workmanship or solid design (in fact quite the opposite, choosing quality here can save you money in the long run) there are some smart ways to keep prices down without sacrificing the end result.

Whether you’re looking to add living space, enhance your property’s value or create a dream kitchen, smart planning is key to keeping your extension on budget and ensuring you’re thrilled with the space.

1. Define your exact requirements

Before starting, precisely define what you want from your extension and how you’ll use the space. A simple design typically costs less than complex architectural plans, so consider your must-haves versus nice-to-haves to avoid scope creep and unnecessary expenses. Developing a precise understanding of your requirements makes it easier to brief the team working on your extension and prevent costly mid-project changes.

2. Research planning permission early

When building an extension, understanding local planning regulations can save money by preventing potential expensive redesigns. Having planning permission rejected or contested is always frustrating, but even more so if it’s due to typical restrictions in the area, so make sure to check specific building restrictions that might impact your extension plans. 

It’s also worth investigating your local council’s permitted development rights to understand what extensions you can build without full planning permission, as this can save you money on application fees. If you’re using an architect, make sure to factor in the fees for their architectural drawings into your budget.

3. Budget strategically

Creating a comprehensive budget for your extension can make your project more cost-effective in the long term. Seeing the cost of everything mapped out from start to finish helps prevent overspending and also allows you to think more critically about which elements you want to invest more or less in. Develop a detailed, realistic cost breakdown that accounts for labour and materials, all potential expenses and build in a 20% contingency fund if you can to handle unexpected challenges.

4. Get multiple detailed quotes

It’s always wise to do your due diligence when it comes to comparing quotes, but especially so when it comes to a big project like an extension. Don’t just compare overall cost, but take a comprehensive approach: request quotes that provide a detailed breakdown of work, materials and timelines, and compare contractors based on their reputation, previous project portfolios and professional certifications. It’s important to look beyond the bottom-line price to understand the full scope of each proposal.

When you book site visits via The Page, our in-house renovation coach Thomas can also help you evaluate your Pager quotes. From assistance deciphering each line (there’s sometimes some industry jargon in there) to giving advice on what’s standard pricing, having an expert eye on your proposals adds another layer of faith that everything you need is covered.

5. Consider timing of construction

Construction costs sometimes fluctuate seasonally so the timing of your extension can impact the overall price. Labour costs often increase in winter as the adverse weather makes jobs more difficult, which in turn can increase your timeline. If you can be flexible, the spring and summer are most favourable times to build an extension. 

6. Embrace a simple design

Complex architectural designs can dramatically increase extension costs. Rectangular or square footprints are typically easier to construct and therefore cheaper. Sticking to standard ceiling heights that don’t require complex engineering and straightforward roofs are a good way to keep costs down.

7. Maximise existing structural elements

One of the best ways to save money is by working intelligently with your current home’s structure, which can help you minimise groundwork expenses. Where possible, stick to your existing foundations to reduce the cost of structural modifications. 

8. Be savvy with material choices

Your choice and source of materials can have a huge impact on your budget. Consider timber cladding for affordable and attractive exterior finishes and standard roof tiles instead of premium or custom options. Rather than shipping materials from abroad or across the country, source materials locally to reduce transportation costs. 

9. Book a contractor that doubles as a project manager

Managing aspects of the project yourself can significantly reduce overhead costs. However, this approach requires sufficient time, basic construction knowledge and the ability to coordinate multiple people and moving parts effectively. If you can’t afford a project manager, some experienced building contractors can take on this role for you. Our Pagers do just that: they’re typically small business owners who’ve honed their skills in bigger construction companies and now employ a tight-knit team themselves. This size of business is perfect for managing extension projects as the main contractor can be both hands-on and delegate efficiently, while offering very good value for money.

10. Procure materials proactively 

Directly purchase materials when possible, looking for opportunities during sales or clearance events. Surplus or discontinued lines can offer substantial discounts, but if you go down this route it’s wise to buy extra just in case something goes wrong – otherwise you might find yourself with mismatched tiles or cabinetry. Look to your builder for trade discounts too; many have good working relationships with suppliers that they can share with their clients.

11. Prioritise essential spaces

Focus the majority of your budget on high-impact areas that add the most value and functionality. Kitchen extensions and ground floor living spaces typically offer the best return on investment, but it all depends on how you personally want to use your new space. If you’re doing a two-storey extension, you could first focus on the ground floor and then the second floor to split the cost over a longer period of time.

12. Mix value for money with wow factor

You can save money by choosing a combination of more budget and premium fittings and fixtures, so make sure to do your research before committing to anything. In some cases, you’re simply paying more for a brand name rather than superior quality. Focus your spending on a few key elements that will transform your space, while making practical choices elsewhere. Statement pendant lights above a kitchen island, for example, can elevate the entire room while costing far less than premium cabinets.

13. Choose contractors wisely

Look beyond simple pricing when selecting a contractor. Evaluate their reputation, previous project portfolios, client testimonials and professional certifications. A slightly higher-priced contractor with the experience and track record to back up their cost can save you money in the long run by avoiding mistakes and ensuring high-quality work.

Knowing where to begin when looking for contractors can be overwhelming. At The Page, we’ve already done the hard work of discovering London’s hidden gems: our Pagers are top-quality, competitively priced and hands-on. Our renovation coach can match you with a shortlist perfect for your project and budget within 24 hours.

14. Hire a pre-vetted contractor

Take advantage of networks that understand the nuances of home extension projects and can apply a critical eye to contractor’s work and professionalism for you. Our Pager vetting process is extensive: everyone we work with has had thorough background and reference checks, plus aligns with our expectations for high-quality work and service. Our renovation experts visit at least two completed projects for quality control before onboarding anyone new.

15. Opt for built-in elements 

Built-in features like window seats or clever storage solutions can create both wow factor and add practical value, often costing less than equivalent freestanding furniture.

16. Consider standard sizes

Utilising standard-sized building components can dramatically reduce your overall project costs. Choose windows, doors and materials that come in standard dimensions to minimise custom manufacturing expenses. This approach not only saves money but also simplifies the installation process and reduces potential complications during construction.

17. Look into sustainable materials 

Investigate innovative and cost-effective material options that can provide both quality and affordability to save money. Recycled glass, timber, wood and steel are not only cheaper but more sustainable. Locally sourced options can also be cheaper due to reduced transport costs, as well as doing their bit for the environment.

18. Think long-term about insulation

Invest strategically in high-quality insulation to create long-term financial benefits. Quality insulation can reduce ongoing energy costs, potentially qualify you for green building incentives and improve your property’s overall value. While the upfront cost is likely to be more, take the long-term view if you can and consider the total lifecycle cost of your insulation choices.

19. Reuse and recycle

Salvageing usable materials from your existing home is a good money saving hack. If you’re relocating your kitchen, for example, is there anything that could be repurposed in your new space? Tiles, cabinetry, appliances and lighting fixtures can all be relocated, and sometimes simply being in a new setting can give things a new lease of life. Or if you want a fresh space, consider selling surplus materials online to offset project expenses.

20. Minimise structural changes

By avoiding major structural modifications, you’ll automatically keep costs down. Try to avoid changes to load-bearing walls or making foundation alterations as these can really increase your spend.

21. Plan your electrics and plumbing smartly

Think about your existing plumbing and electrics in relation to your new extension. Where do the pipes and cables run? By using standard connection points and designing your extension to work with existing utility infrastructure, you’ll create less work for your contractor – i.e. less money on unnecessary labour costs.

22. Consider a two-storey extension

Evaluate the cost-effectiveness of different extension types carefully. Two-storey extensions often provide better value per square meter compared to single-storey options, as a lot of the structural work is already in place. If your budget and planning restrictions allow it, it’s worth considering going bigger for the potential return on investment in the long run.

23. Look for win-win design and budget opportunities 

There are some instances where architectural decisions can create impact without significant extra cost. A double-height void above your dining area might only sacrifice a small amount of floor space but creates a striking sense of volume and light. Well-placed roof lights can flood your space with natural light while costing less than an equivalent area of bi-fold doors. You can also consider using standard materials in interesting ways – like simple metro tiles laid in a herringbone pattern or standard-sized windows grouped together to create an architectural feature.

24. Mitigate risk with insurance and warranties

A house extension is a huge investment, so it makes sense to protect it through comprehensive insurance and warranties. Insurance wise, contractors aren’t required to have insurance unless they have employees; employer’s liability insurance will cover any injuries on site. Your existing home insurance might protect your home while work is going on but it’s common for this to be limited, so double check before you begin as extension or renovation insurance is also an option. 

Make sure to check the warranties of products and materials before purchasing, or if your contractor is buying the white goods, ensure the details are clearly stated in your quote or contract. A workmanship guarantee also goes a long way to ensuring peace of mind and can save you money further down the line. All of our Pagers are proud to stand by their work and ensure quality and longevity, offering two-year workmanship guarantees. 

25. Use digital planning tools

Leverage technology to optimise your extension planning. Utilise 3D modelling software, virtual design platforms and cost estimation tools to create precise plans and identify potential cost-saving opportunities. Digital planning can also be helpful for visualising the project, so you can make more informed and confident decisions.

26. Energy-efficient design

Incorporating forward-thinking design principles that prioritise long-term efficiency can save you money in the long run. Think about natural lighting strategies for your house extension: more windows or glass doors, for example, can reduce your reliance on artificial light and have a knock-on effect for your energy bills. 

If possible, think about passive solar design principles, which essentially use natural heating, cooling and lighting to maximise energy efficiency. Things like minimising north-facing windows as they lose more heat than they gain, choosing materials that absorb and retain the heat of the sun like concrete brick and stone, and using different types of glass for different orientations all play into this.

27. Be wary of DIY

If you’re on a tight budget, DIY can understandably sound very appealing. But with such an important project like an extension, it’s not wise to take on much yourself unless you’re very confident in your skills. Even the smaller, finishing touch jobs like painting involve a lot of skill (not to mention time) and if you have to get a decorator in to fix it in the end, you’ll likely spend more money than if it was incorporated into your initial project fee.

28. Be flexible (if you can) 

Where possible, approach your extension project with scheduling flexibility. Good contractors are busy contractors, so if you can be adaptable with your start date and timeline, you’re more likely to be able to book the renovation team you want, and take advantage of competitive pricing and availability.

29. Be efficient with waste 

Rather than automatically booking a large skip for the duration of your project (which can cost up to £300 per week in London) think about which specific stages of the build you’ll need waste removal for. Can anything live in your garden for a while? It won’t be pretty but it could cut costs. You can also look to local recycling schemes and donation points. 

30. Stick to the plan

When you have your final design confirmed, you should consider it signed and sealed – no more changes. Deciding halfway through that actually underfloor heating is a good idea or you’d like your lighting sockets in a different place is only going to increase your spend (and timeline).  If you do change your mind during the process, make sure to communicate quickly and clearly, and get the new plans in writing to make sure that everyone is on the same page. 

31. Stay on top of your project

Keep a close eye on your extension finances from start to finish. Track expenses meticulously, identify potential cost overruns early and communicate openly and regularly with your contractors to prevent budget creep.

32. Think about the future 

Design your extension with long-term flexibility in mind. While you want to love and use your extension immediately, think about how it will be able to adapt to changing family needs and potentially improve your property’s future resale value. There’s no point in investing thousands into a space you’ll grow out of. Versatility is key!

33. Understand permit and inspection costs

Budget carefully for all regulatory requirements. Account for necessary inspections, local compliance costs and potential permit fees. Understanding these expenses in advance prevents unexpected financial surprises.

34. Figure out payment terms that work for both parties 

While it’s not advisable to pay for everything upfront, most contractors will require a deposit, particularly for a large job like a house extension. Discuss staged payments that protect both your financial interests and the contractor’s cash flow to 

35. Go for high-quality workmanship over everything else

If you’re on a tight budget, sometimes you do have to prioritise certain things and make some sacrifices. If this is the case, always choose high-quality workmanship over high spec fittings and fixtures – it will save you money in the long run.

Find a home extension contractor with Thomas at The Page

Planning an extension doesn’t have to be overwhelming. At The Page, we specialise in matching homeowners with trusted, hands-on contractors who can bring visions to life at competitive prices – without sacrificing quality. We’ve already done the hard work of finding exceptional contractors: we team up with Pagers not just for their skills but their approach to project management and communication.

Ready to start your extension journey? Our renovation coaches understand both the practical and emotional aspects of extending your home, providing expert guidance at every step. We’ll help you understand the process, connect you with the right contractors for your extension, and ensure you feel confident and supported from start to finish.