The benefits of doing a ground floor extension and a loft conversion together

Here at Home Tales, we specialise in home extensions. Most of our projects are either ground floor extensions or loft conversions, but we also undertake first floor extensions, garage conversions, roof terraces, and many other types of renovation work. Some of our projects are doubles, meaning that the homeowner wants to discuss the possibility of a ground floor extension and a loft conversion. There are a lot of advantages to undertaking a double project and we thought we would run through some of them for you.  

Maximise space.

One of the biggest benefits of a double extension is the amount of space it will add to your home. Generally (depending on the existing layout of the property) the most effective way to extend is either through a ground floor extension or a loft conversion, so doing both gives you the ultimate extension duo! Ground floor extensions vary in how much SQM they add to your home, but you can expect 10-20SQM for a typical extension on a standard Victorian terrace. For ground floor extensions it’s not necessarily the additional SQM area that transforms the room, but the addition of the space. What do we mean by that? Ground floor extensions do not typically add a new room to the property, instead they extend the size of an existing room. For example, this side return in Wandsworth only added 11SQM to the room but it totally changed the shape by increasing the width of the room. These extensions might be small, but they have a significant impact!

A loft conversion tends to add more physical space, averaging 25SQM to 40SQM. In contrast to ground floor extensions, they don’t usually extend an existing space, but create entire new rooms or in most cases, an entire new floor to the property. We extended the loft of this family home on Pulborough Road, SW18. The loft conversion added a massive 38SQM to the property which enabled the creation of two huge bedrooms and a bathroom. This took the house from a modest 3-bed, 1-bathroom to a generous 5-bed, 2-bathroom.

Design together.

There are two huge benefits to designing a ground floor extension and a loft conversion together. The first is cost. It is nothing like double the design fee to undertake a double project. It becomes much more cost efficient as we can get everything measured in one survey, discussed as one project, and drawn up together. In addition to this, we always survey the entire property for a double project so if you have any modifications you wish to make on the first floor these are included as standard. The planning application is more straight-forward, and you only need to pay the planning fee to the council once (instead of twice). The building regulations pack is also simplified, as the engineering can be done to account for the other extension. For example, if the engineer can see there will be a loft conversion and an increased load on the property, they might modify the ground floor extension structure to account for the weight. The other benefit to designing a double project is you can design the entire property in unison. Decisions that are made on the ground floor might impact the first floor and loft, and vice versa. You might decide to put your utility area in the loft, or to create a laundry chute which runs throughout all floors of the property. You might decide the first-floor bathroom doesn’t give you the luxurious free-standing bath you desire, so more space is needed in the loft for a family bathroom. There are endless design possibilities and decisions are much better made when you are thinking about your entire design rather than just one floor or section at a time.

The Build.

One question we are frequently asked if whether it would be more cost efficient to build a double project together. While it is considerably more cost efficient to design as one, you don’t see the same benefits on the build side. Mainly because the labour and materials are the bulk of the build cost, and the project is very much ‘double the work’. You will save a bit on skip collections and parking bay suspensions, but nothing significant enough to impact the cost drastically. You might find a builder who gives you a slightly sweeter deal for the double project as it gives them a bit more security in allocating resources for a longer period, but again, it won’t be significant. The biggest pro of building a double project in one go is the limit to disruption. Extensions are a big upheaval to a property and the homeowners within. If you undertake a double project, it’s harder to live in during the works. If you do choose to live in it will slow the build down as the projects will have to accommodate your living quarters! If you chose to move out however, works can commence faster and more efficiently.

If you want to discuss a double project or a single project, we would be delighted to help. It’s very common to discuss the possibility of two projects on our consults but you don’t need to commit to the double project from the outset. It’s very common for our team to explain the pros and cons of the double project and to even offer multiple quotes for both options, so you can make an informed decision on whether you want to go for both or select them individually. Call us on 0207 043 2378 or email our wonderful team at to find out more. You can also book a consult directly via our live diary here.

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