Simple and Comprehensive Guide to House Extensions

Are House Extensions Worth the Hassle

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Recently we had a pleasure of writing and publishing an article about loft conversions. This week we have decided to focus on house extensions. Which are equally popular solutions to increase the size of your house due to ridiculous real estate prices.

Funnily enough such attic alteration is often called house extension as well. Quite understandable, at the end you extend your leaving space.

However, we will leave this aside and focus purely on modifications that involve increasing size of your house. Whether it’s by building brick-and-mortar back or side addition or glazed conservatory.

The main reason we have decided to keep these two home improvements separate is because the process in both cases is completely different.

In the event of loft conversion all you do is adapting unused space for additional room. Meanwhile house extension, the way we understand it, is adding more square metres to your building. As a result you need to tackle this challenge in a different way.

Hence, below you can find everything you might need from planning perspective. Including permissions, regulations, finances, designs and most importantly possible obstacles that might make you wonder if it’s really worth it.

Ready? Let’s dive in!

Where do I Start if I Want to Build a House Extension

Before you start any sorts of works first you need to make sure you actually can build a house extension. Good news are that generally speaking it is allowed under permitted development rights. However, there are few things you need to take under your consideration.

Planning permission

You don’t need planning permission as long as you can follow below requirements:

  • It can’t be higher than the highest part of the roof
  • The materials have to be similar in appearance to existing house
  • No raised platforms, verandas or balconies
  • Single storey extension can’t be higher than four metres
  • More than one storey extensions can’t extend beyond the original house’s rear wall by more than three metres
  • Single-storey rear extension must not extend beyond the rear wall of the original house by more than three metres if an attached house or by four metres if a detached house
  • Two-storey extensions cannot be closer than seven metres to rear boundary
  • No extension forward of the principal elevation or side elevation fronting a highway
  • If you plan two storeys extension upper-floor, side-facing windows have to be obscure-glazed; any opening is 1.7m above the floor
  • Single storey side extensions with maximum height of four metres and width no more than half that of the original house
  • Rear wall of a detached home can be extended by 8m to the rear if it is a single storey property, and 3m if it is double storey. This is reduced to 6m in a semi or terraced house

And now it’s the best part. Your extension is no more than half the area of land around the original house – curtilage.

The “original house” is seen as it was in 1948; after this date how it was newly built.

In human language that means that if the building was built prior to 1st of July 1948 it doesn’t matter what has been done before that date. All alterations to that day are treated as if it was built this way.

Other legal requirements

Ideally you want to avoid going through painful process of planning permission to get an approval. Unless you live in conservation areas, permitted development rights are restricted and you will have to contact your local officer before you start making any plans.

Other than that it’s always a good idea to get in touch with your neighbours in advance. Especially if you share a wall or you are planning to build your extension really close to your neighbours property.

In such case you will need Party Wall Agreement and if planning permission is required they will be consulted by local authority. A bottle of good red can do no harm.

Personally I would also inform your insurance company to recalculate your premium.

Extension will increase the cost of rebuilding your house, so they need to take it under account. Besides, there is a risk that your property might get damaged during works.

Building regulations

No matter if you need planning permission or not this modification is still a subject to building regulations. Basically everything that applies in other works that involve new heating appliances and electricity, but also fire safety, energy efficiency, damp proofing and ventilation.

Of course if you are planning structural changes, like the removal of load-bearing wall you definitely should consult it with building control and experienced builder. This is serious stuff and can lead to tragedy if it’s not done right.

Where do I Start if I Want to Build a House Extension

What to do When You Can’t Afford House Extension

Once you have taken care of all legal stuff, you can start thinking about funding the entire endeavour. You have to bear in mind that it will not be cheap.

The average cost per square metre for an extension outside of London can be anywhere between £1,200 and £1,750. If you are planning additional bathroom add another £5,000 and another £10,000 for new kitchen.

For second storey the additional cost is usually only around 50% of original price.

It is smart to add at least 10% for architect and building regulations and planning application fees. And another 5% for contingency planning. All in all fairly small 5m x 3m extension will cost about £26,000.

What can you do if you can’t afford to spend such money? There are several options. First is remortgage or adding this amount to your current mortgage.

But you should also go ahead with very simple design and simple groundworks. All fancy curves and complexities will increase the price. You can also use as many off-the-shelf ready-made products as you can.

They will be cheaper than made-to-order.

Avoid cowboy builders and planning permission at all costs. Look for problem-solving builder with multiple skills. It can’t be stressed enough, right specialist means everything.

Look for problem-solving #builder with multiple skills. It can’t be stressed enough, right specialist means everything. #problemSolving

In case of Party Wall Agreement you can save a lot of money if your neighbours will sign a weaver. Otherwise you will have to pay 700 quid for surveyor or more if they will want to use their own independent surveyor.

Either way you have to pay.

If it’s still not enough and the project is too expensive ultimately you can consider alternative in shape of loft conversion or a conservatory.

Is it Better to go for House Extension or Conservatory

As mentioned already at the very beginning we have covered loft conversions in one of our previous articles. You can find it below. It’s very thorough and informative so I am sure it will be very beneficial.

Maybe that’s the right option for you? It’s much less expensive and much less problematic.

Another option you might want to pursue is simply building a conservatory, rather than house extension. Both of these solutions have pros and cons, and I will try to present them in a way that will help you to decide, what works best for you.

Is it Better to go for House Extension or Conservatory

However, conservatory is much cheaper. Nine square metres will usually cost between £7,000 and £13,000.

The first thing before making a decision is to clarify what this additional room will be used for. While brick-built extensions can have multiple purposes, traditional conservatory won’t be suitable for extra bedroom. But it will be just perfect for dining room, office or living room.

Benefits of conservatory

  • Quicker to build, usually within week or two with a little disruption
  • Very bright and brings a lot of light thanks to large glazed areas
  • Gives you a feeling of being in the garden, but with indoor comfort
  • Readily available in different shapes from long list of suppliers
  • They just look great

Downsides of conservatory

  • Glazed walls need cleaning more often
  • It can be really noisy in event of rain or snow
  • Problematic to use during hot and very cold months

Benefits of extension

  • It’s much more functional and can be anything you like
  • The results can be stunning if supported with enough funding
  • It can be used all year round
  • Integral part of your house and more flexibility in term of size and location
  • Adds more value to your property than conservatory

Downsides of extension

  • Much more expensive than conservatory
  • Building process is much longer and disruptive
  • Depending on the project it can look less attractive

Are House Extensions Worth the Hassle

Now you have to answer yourself a question is it all worth it? It’s purely subjective and there are many things you will have to cope with. One of them is of course building works. It can take weeks or even months and that’s why many people decide to leave their house for a while.

Yes, it’s an additional cost, but since the builders do not have work around your life it goes much quicker. It might also mean some financial benefits.

Other tender spot can be dealing with architect and comply with all building regulations. On top of that you either have to move out for a little bit or or adjust your life to workers doing their thing, day in, day out.

Not to mention the project itself and the architect… it can be really painful, but guess what? I can totally understand it. The entire process can be really stressful.

I have also read in one of the forums about a lady who was totally stressed out even by the project!

Who could blame her? The architect appeared to be “technician architect” so he took his time. Honestly speaking, this is ridiculous. If you need any help just give us a shout at our chat on the right hand corner or drop us a line at – we will be more than glad to help.

#Building a house extension can be really stressful, if you can move out for few weeks. It will also allow your contractors to work much faster #houseExtension

Are house extensions worth the hassle? It’s you call, but have a look at these designs and imagine how beautiful your extension can be 🙂 in my personal opinion they’re worth every penny and every possible obstacle.

The extensions give you freedom and possibility to express yourself. There is no price tag on that feeling.

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