Will an Extension add value to your house and other common building questions answered

Now this week is a very packed episode on the podcast and I urge you to listen because it is super useful as well. Firstly, we are discussing floor plans and how it’s important, before you so much as LOOK at a paint chart to decide if your rooms are in the right place for the way you live. Just because the kitchen has always been at there doesn’t mean that’s the best place for it. Then we interview Sophie’s husband Tom, a builder of some 25 years standing, who tells us how to really add value to your home and how to get the best out of your builders and architects. You do NOT want to miss this one.

the loft conversion at
the loft conversion at

Now a floor plan can be so useful – sometimes a stripped back aerial view of where the doors are, the thickness of the walls etc can be much easier than being in the room and not being able to see through a wall to the other side. I use graph paper, a black pen and pieces of paper cut to the scale size of the vital items of furniture.

I appreciate I’m  in a minority starting with the floor plan, but I have always found it incredibly useful to be able to see the position of the bedrooms in relation to the bathroom, or the kitchen in relation to the garden. I have known several houses where the kitchen is at the back preventing anyone from sitting and looking at the garden, and other houses where internal walls prevent a through view of the house to the garden when you come in from the front door. Of course, different people have different priorities, but I think it’s always worth trying to take an objective view and deciding if it would improve the way if you live if a loo was added there, because the floor plan shows you there is space, or the kitchen moved back into the middle of the house so you can create a seating area overlooking the garden.

Sophie Robinson has a huge bedroom with an en suite that can barely fit two people
Sophie Robinson has a huge bedroom with an en suite that can barely fit two people

By the same token, as I have said before, a large en suite and a smaller bedroom will always feel more hotel than a huge, partially un-used bedroom with a cramped en suite. Looking at a floor plan can help you spot these things as it’s a black and white diagram that doesn’t distract you with features and colour schemes. It also allows you to see at a glance if you can save any space by replacing traditional doors with space-saving sliding ones.

You need to get the layout right so that it works before you get over-excited about the colours. And that’s not to say you can’t have a scheme in the back of your mind but do look at the house floor plans and room layout first.

We are conditioned to accept the rooms are where the estate says they will be. A classic example is that the television points tend to be diagonally opposite the door so that it’s the first thing you see when you come into the room. It’s perceived as expensive to move the aerial point so we end up decorating our entire sitting room around the tv either trying to disguise it or inadvertently making it the focal point of the room.

Sophie Robinson's large light filled sitting room is only used at night
Sophie Robinson’s large light filled sitting room is only used at night

Consider flow from the garden and moving around the house and ask yourself – is that where I actually want this room? Years ago I researched a piece for The Financial Times about how people live in Australia and was told that the traditional sitting room was evolving out of existence (this was in Sydney 10 years ago and may not be true for everyone so take it as a hypothesis only) as people were creating outdoor sitting rooms and the “front room” was now being used as an extra bedroom, or more likely these days, a home office.

Sophie has a small dark kitchen at the north end of her house where they spend all their time. The south-facing huge sitting room (above) is used only in the evenings (and for podcasting!). She had been contemplating replacing the 1980s conservatory with an extension including a new kitchen with huge glass windows but now, given the rising cost of building materials and labour, which has almost doubled, she is now wondering if she should rebuild the conservatory as a garden room, which would be much cheaper than the original plan, turn the sitting room into a lovely light-filled kitchen/ dining/living space and make the old kitchen into an evening snug. This would save money and still improve the way they live.

It’s not cheap to re-site kitchens and bathrooms of course, but it’s probably cheaper than building a whole new extension.

Everyone gathers in Sophie Robinson's small dark kitchen
Everyone gathers in Sophie Robinson’s small dark kitchen

There is a common assumption that you need to add more space but it might simply be that you have enough space it’s just in the wrong place. And don’t forget that adding an extension to the back will make the rest of the house darker and, therefore, will you want to spend time in it?

Or another example: parents often take the biggest bedroom which they use only at night, whereas children, who have the biggest toys and spend the most time in there, tend to be in the smaller rooms. Sophie has a huge bedroom and a tiny en suite that can barely fit two people and it would make sense to move (or add a new) internal wall to create a smaller sleeping space and a bigger bathroom.

It’s all budget dependent of course but it’s worth having the conversation – if only to make your certain that you don’t need to move things around.

To learn even more about the practicalities of moving rooms and extending we spoke to Tom Pike, Sophie’s husband, who ran his own company and did his first renovation while a student at Cardiff University.

So the $64m dollar question. What actually adds value to a property? Is it basically more square footage?

A loft extension will add value and you should get your money back as houses tend to be valued by the number of bedrooms
A loft extension will add value and you should get your money back as houses tend to be valued by the number of bedrooms

If you are adding a bedroom or two and a bathroom, you will get your money back in resale – you may even make some money because houses tend to be priced per bedroom so an extra bedroom will increase the sale value, he says.

But for kitchen extensions, you have to do that as a lifestyle choice because, in the vast, majority of cases, you will not recoup the full cost of doing it. If you are lucky, says Tom, you will get some of it back.

“It will make your house worth a bit more and it will make it more saleable because it will be a nicer house so you will get a higher sale price but you won’t get the full cost back.”

Your architect may not be up to date with building costs.

Tom also warns that architects aren’t always up to date with the cost of building and labour so don’t take their calculations as read. The cost of building materials has rocketed over the last two years so you must have a conversation with the architect and the builder to get a more realistic idea of what a project will cost and then you can trim the design accordingly.

Offering to do the painting yourself, or buying a cheaper kitchen probably isn’t going to make enough difference. If you need to reduce the projected cost by a third, you are going to need to downsize the architect’s ideas.

building into the side return is a lifestyle choice - you are unlikely to recoup the full cost of doing it (image via the modern house)
building into the side return is a lifestyle choice – you are unlikely to recoup the full cost of doing it (image via the modern house)

Should I project manage myself?

What if you project manage yourself to try and save money? We see this on Grand Designs all the time so is it a realistic option? Tom says simply: “Who are you and what are your skills? You need to understand the process of building. Even my friends who are carpenters have tried to do this but have come unstuck. You can lose so much money getting stuck in the process – if you haven’t booked the plasterer to co-ordinate with the electrician. If the plumber is called to an emergency and then the plasterer can’t do his job. And don’t forget you will be a one-off client – many builders have regular work with other firms and if they are called to a regular for a last minute emergency they will go there to safeguard their regular work rather than come to you. An entire project can unravel quite quickly. If you want to project manage you need to be three steps ahead of what is happening on the ground.

“People don’t realise how hard it is to project manage and if they have seen it done and it was all seamless they think they can do it themselves, but they don’t realise how much experience and knowledge the project manager has brought to the project to make it seem that way. It can be an absolute nightmare; all you need is one part that is missing when the plumber needs it and he disappears and says he can’t come back for a week and suddently everyone else is affected by that change in schedule.

“On a smaller project where you might have everyone on site every day this is less of an issue.”

kitchen extension via the modern house
kitchen extension via the modern house

How to find a good builder?

Three or four quotes is enough – more and you are wasting people’s time. Try for some recommendations – either via reviews or friends and colleagues. When the quotes come in take a very good look at how they are presented, says Tom.

A detailed line by line quote will give you a good sense of the firm behind the quote and how organised they are. A sheet of A4 with a couple of lines of description – “to build your extension will cost £xxx”  and a verbal assurance that they will see you right is a red flag.

You might decide to change the spec of the doors and you don’t know what the builder allowed for the original doors so you have no control over what he is going to charge you when the plans change.

Always ask about “variations” or “extras” – there will be changes and you need to know what the charging process is so you can discuss issues as they arise.

laura jackson invites Kate Watson-Smyth and Sophie Robinson on a house tour for the Great Indoors Podcast. Her loft conversion keeps the original shape and is covered with tongue and groove. The bathroom floor is laid with a small hexagon mosaic tiles from Topps Tiles. #tongueandgroove #loftconversion #madaboutthehouse #thegreatindoors
adding an extra room in the loft is money well spent – this is Laura Jackson’s loft bathroom

I hope you have found this useful – do bookmark it – and many thanks to Geberit for sponsoring the show and allowing us to find and share these tips with you. 




















Tags : add value to your homebuilding advicehouse extensionsthe great indoorsthe great indoors podcast
Kate Watson-Smyth

The author Kate Watson-Smyth

I’m a journalist who writes about interiors mainly for The Financial Times but I have also written regularly for The Independent and The Daily Mail. My house has been in Living Etc, HeartHome and featured in The Wall Street Journal & Corriere della Sera. I also run an interior styling consultancy Mad About Your House. Welcome to my Mad House.


  1. We gave up our master/main bedroom and bath when our in-laws moved in during the early pandemic. It made sense that people who spend more time in bed and the bathroom have a toilet all to themselves and more square footage so they didn’t feel so cramped spending most of their day in a single room. After they moved into their own apartment, we decided to give it to our children. This has benefited us in several ways: 1) 3 kiddos and their stuff in the largest room means the whole house is cleaner and tidier, even their room is tidier now that there’s more room for storage furniture and everything has a place; 2) my husband and I now have a south-facing bedroom and wake easier and with less grumpiness, we didn’t even anticipate that so it’s such a nice surprise; 3) the smaller bedroom for us means we had to reevaluate the amount of stuff we were keeping in the bedroom – we reduced our wardrobes, linens, furniture, and stopped using our bedroom as a giant “junk drawer” for things that don’t go elsewhere and it is so much pleasanter to go to bed; 4) reducing our stuff was a gateway to reducing distractions allowed in our room and next to the bed, we sleep better with less gadgets, less indicator LEDs, and no giant TV centered in the room; 5) there was enough space in the big bedroom to separate the kids’ beds and now the littlest can’t annoy the oldest in the early morning and at bedtime since their beds are across the room from each other; 6) when people are coming over, there’s less work for me to do to get the hallway bathroom ready – my husband and I are the only ones who use it regularly and our kids’ messes of toothpaste, soap drips, etc is contained where my guests are unlikely to see or be affected by it.

    1. Thank you for such a wonderfully detailed comment. I’m sure this will be helpful to so many people and how interesting that a south-facing bedroom has made you less grumpy – I wonder what that’s about!

  2. Have to say I find it interesting people don’t think to ask for a detailed quote broken down line by line. The advice given to me (by my architect actually but good advice as it turns out!!) is to specify as much as possible before you go to tender with your builders. Make sure you have specified doors, architrave, door handles, radiators, the right type of slot drains or whatever it is. If it is specified, the builders will quote you for those items (or should – I always double check!). I also make sure I have considered everything before going to a builder – slightly depends on the timescales but I’ve probably already worked out my bathroom fittings, lighting, where exactly the plug sockets, tv points etc are going before I even go to tender. And I always ask for a fixed price quote (i.e. no changes even if the building materials go up in cost etc) – obviously any changes you request are to be agreed and an additional price, but no unexpected surprises this way. I was also interested in Tom’s answer about project managing. While I totally agree that lining up different trades is very difficult as a non-professional, I have always used a builder who brings in all the trades but still project manage the overall build myself. I have found architects will happily charge a fee to oversee, or project manage as they call it, make sure the right amount is being invoiced on whatever agreed schedule etc, but I prefer to take charge myself. I let the builders ensure the electrician, plumber, plasterer etc is on site on the right day, but I oversee everything, make an annoying list of questions almost daily (sorry builders! but got to get it right!), go over each invoice with a magnifying glass to make sure I understand everything being charged (I am a very prompt payer though to make up for my annoyingness!) and make sure anything I am required to choose or order is on site in plenty of time – tiles, bathroom fixtures etc. Always worked very well for me and have been exceedingly happy with the finished result each time. I am somewhat of an opinionated so and so though, so even though I have limited specialist knowledge, I know what I want and what it should look like, and I make sure I know the plans inside out and back to front, which I guess helps.

    Have to say, I also love a floorplan, although I tend to mess around in Powerpoint rather than on paper (and yes I know I should use a proper program but as a mere amateur this seems easier!).

  3. This is so helpful, also the bit about the TV points made me laugh as it’s so true!

  4. Excellent blood Kate. We’re builders & we are amazed how people listen to their architects about the building cost. 95% of architects we work with have absolutely no idea of costs, unfortunately.

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