House extensions: everything a homeowner needs to know
This is an essential guide for any homeowner looking to add a house extension. We cover costs, finance, planning, regulations, and have plenty of inspirational ideas too!
11 min read
Why move when you can improve? With a home extension, you can get the space you need, while also being able to stay in the area you love. What’s more, with the right home extension, designed by the right architect, you not only get to enjoy the day to day benefits, but you may also find the value of your property benefiting too.
So, how do you go about creating a home extension?
In this ultimate guide for homeowners, we’ll be helping you explore your options. This will not only include showing you what home extension options you have, but diving deep into the ins and outs of getting your project on site. From planning to building regulations, budgeting to finance, we’ll be leaving no stone left unturned in this comprehensive guide.
Home extensions come in all shapes and sizes, so finding the right one for your property only requires a little bit of research. Here are some popular extension types you might consider…
Extending the front of your home has the major benefit of keeping your rear garden intact. This extension can be used to enlarge your living room, create a new ground floor bedroom, or even just add in a new porch. However, as this extension will be visible on street level, it will be subject to more planning scrutiny.
Situated to the (you guessed it) side of your house, this extension is a fantastic option for anyone looking to put a sad looking alleyway space to good use. A side house extension can be used to level off the rear of your home and create a compact new addition that transforms the property. Though small, these mighty extensions have been used to create some truly stunning open plan kitchen diners. What’s more, you might be able to achieve yours without the need for a full planning application.
If you live in a semi-detached property, there are plenty of extension types for you to explore. With only one side of your property attached to a neighbour, you and your architect can extend your house in a way that doesn’t impact on the next door’s privacy or create any party wall matters. Semi-detached house extensions can also benefit from permitted development rights, which can help during the planning stage.
It can feel a little daunting to extend a terraced house, but you needn’t be worried. Although you’ll need to factor in the privacy of your neighbours, along with their right to light, you will still enjoy plenty of design freedom. Of course, you should be aware that it’s likely your project will affect either a shared wall or boundary with one (or maybe both) of your neighbours. In this scenario, you will need to ensure you serve a party wall notice and get permission before construction begins.
Extending the rear of your house is a very popular option. Often used to expand key living areas, such as your kitchen, the rear extension is a highly versatile addition and can be used to create all kinds of space. You might opt for a new ground floor bedroom, utility room, home office, or even playroom. You may also use popular glazing, such as bi-fold doors, to create better connection to your garden space and bring lots of natural light into your home.
Flat-pack or prefab extensions are relatively newcomers on the residential scene, but have been rising in popularity over the last few years. Because they’re primarily built off-site, they’re a very cost effective way to extend your home and have much shorter construction times - meaning you don’t have to live on a building site or rented accommodation for very long. However, many flat-pack homes offer little to no customisation, and so you can lose one of the main benefits of extending your home, which is that you end up with a home tailored to your family.
Before you start any project, it's important to work out a budget and a financing strategy. At Resi, our brokers can help you explore different lending options, simply click here to get started.
Overall, the cost of a house extension will vary massively depending on…
How much money can DIY save you on a home extension?
If you’ve got the skill set, doing things yourself can help save you thousands on a home extension. However, you should be cautious about the risks involved. Mess up a key element of your build, especially anything relating to structure, and the cost of repairs will likely cancel out any savings you made at the time.
Therefore, unless you’re qualified, we recommend you stay away from…
When it comes to financing your home extension, many people fail to do their homework and instead rely solely on their savings. But this is just one way of getting your extension off the ground. Make sure you’re also considering these alternatives…
House extension loan
For smaller projects, using an unsecured personal loan could be a good option, depending on the deals available to you at the time. They’re a great option if you’re only looking to cover short-term costs, as they don’t come with set-up fees attached. However, due to the high interest rates, you’ll want to make sure you pay this type of loan back quickly, as well as back sure you borrow less than £30,000.
For larger projects - over £30,000 - you might want to consider remortgaging or securing a further advance. This route is very attractive, as it can utilize both the existing and future equity of your home to get you the amount you need. What’s more, it also gives more flexibility than just using savings alone.
Personal savings
The benefits of using personal savings are obvious. With no lender involved, you needn’t worry about interest rates or payment plans. This is very appealing but there are some downsides to this approach. For instance, it can take time to get your savings to where they need to be and, during this time, inflation can go up, taking your project out of reach. Savings are also quite inflexible, putting you in a difficult position if you’re not budgeting a contingency fund at the same time.
Side extensions are a fantastic way to use up dead space around your property. Typically used to extend older housing stock, a side extension squares off a property with an alleyway present and expands key living areas.
This Lambeth project was completed in 2016, and used the side extension to create a broken plan kitchen/living room - complete with a glass ceiling and exposed brick wall.
A wraparound house extension in Southwark
Many people assume wraparound extensions have to be a massive undertaking, but as this Southwark project shows, they can be very economical. Rather than losing an entire alleyway or a large chunk of your rear garden, a wraparound allows you to take a little from both - resulting in plenty of space but without the sacrifice!
For this project, we combined the wraparound house extension with a matching brick facade and gorgeous Crittal french doors. This creates not only a beautiful kitchen diner, but leaves space to the side for raised bed and a picturesque view for the living room.
Environmentally friendly house extensions
More and more homeowners are becoming more environmentally conscious, especially when it comes to their households. With our homes accounting for 27% of the UK’s carbon emissions, there’s no better place to start your eco-friendly journey. And, luckily, there are plenty of ways to make your home extension plans that little bit greener.
How to build an energy efficient house extension
One of the best ways to bring your carbon emissions down is to ensure your home uses energy efficiently. The three areas to focus on in this regard are…
While each house extension is unique, it’s likely you’ll be running through the same list of tasks as your neighbours. Traditionally, this process has felt fragmented and confusing, but with services like Resi, you can sit back and relax, as our team guides you from Point A to Point B.
You are not legally required to hire an architect.
However, this doesn’t mean you should rule them out. Architects are highly skilled in home design and bring a range of benefits to any project. Some of the most important reasons to consider hiring an architect are…
Once you get started with your home extension project, you can quickly get lost in all the talk concerning drawings. What are elevations? Which do you need for planning?
For most projects, you’ll need the following types of construction drawings to get your project through planning and ready for construction…
When it comes to regulations, you better strap yourself in for a long ride. From planning permission to building regulations, structural drawings to party walls, there’s plenty of hoops you’ll need to jump through before you’re legally ready to start construction.
The main regulations you should focus on are…
Planning permission
Building regulations
Party wall matters
What kind of survey do I need for my house extension?
Surveying your property is one of the first steps of any project, and it is often underestimated how important this stage really is. By producing the existing drawings most of your team will use through the course of your project, getting a high-quality survey can make all the difference to both the results and your budget. Afterall, make a mistake here and resolving the error can be costly.
So, what kind of survey will you need? Your options will include…
Can you build a home extension without planning permission? Yes!
If your project comes under your permitted development rights, you’ll be able to avoid the need for a full planning application. However, this doesn’t mean you’ll be able to escape the planning process entirely. It’s still highly advised you apply for a lawful development certificate, in order to document your project was legal at the point of construction. And, if you plan on building a large rear extension (up to 6m or 8m in length, depending on whether or not your home is detached), then you are legally required to apply for prior approval.
Permitted development rights are great for removing subjectivity from the planning process, but getting the right documentation will take roughly the same time as a full planning application, so if you’re looking to cut down on timings, think again! They also don’t cover all properties and come with strict design guidelines.
Adding an extension to a listed building isn’t impossible, but your options will be limited.
Unlike other properties, you won’t benefit from permitted development rights, so a full planning application will be required. You’ll also need to obtain listed building consent, which will take into consideration:
Resi Design Ltd. trading as 'Resi' | Company No: 10471125
We are proud to employ architects registered with the Architects Registration Board and were awarded the mark for The Mayor's Good Work Standard for fair pay & conditions, wellbeing, skills, progression, diversity and recruitment.
