Everything you need to know about glass box extensions

During lockdown everyone was stuck at home wondering about what the world would look like when we were allowed out again. At the same time everyone was inside looking out, often through small windows or French doors.  Most people, especially those with families, were dreaming of more space. 


Imagine however if instead of a small window and not enough space you could add a sheet of glass where your window is –  floor to ceiling wall to wall – just like those high tech offices you see popping up all over the place.  Well you can.

Glass boxes are made of exactly the same glass as those high tech offices. It is extremely strong, in fact you can stand on it quite happily and it won’t break (please don’t try this at home though!) 

How did glass boxes become so popular?

Many years ago, English Heritage were involved in a project to join two Edwardian mansion style houses with a walkway.  Many plans were drawn up, but none were acceptable as they all altered the structure of the original buildings or were pastiches of the same.  Then one architect came up with the idea of a covered structural glass walkway, this had many advantages, but primarily made no structural changes to the original houses as it was in effect “stuck on”.  This was approved and the rest they say is history.  Residential properties began screaming for these as “in fill” extensions, they didn’t damage the original structure, let in lots of light into otherwise darkened rooms, were comfortable and warm, not like the conservatories of the 80’s-00’s and added space to houses.

Can anyone have a glass box?

Yes is the simple answer.  They are made in all shapes and sizes and being glass it is very easy to custom make them for your home.  They can be:-

·       infills between a garden wall and an existing extension

·       A full width extension across the back of a building

·       An extension taking in the patio area of our garden with fully opening doors for all weather patio’ ing.

·       A pop out window to replace an existing one

·       A double height extension

The list is really is endless.

Are they expensive?

No, in the scheme of things.  Like with all things you get what you pay for, most of the cost is any modification to your existing structure you want or ground works to move drains etc. (builders have a habit of placing them just outside doors). An average glass box, not including the ground works is around £30-£35k and you end up with a space that looks like this….

How does the build process work?

Like any build project a full survey is done, designs are discussed with you and if needed planning permission sought.  Quite often, like in this case, the work can carry on outside without you being involved and only when they need to “join” the outside to the inside will builders need to have access.  As you can see in this build there are two vertical pieces of glass running from the top of the picture towards the two doors, these are the glass structural beams and rest inside two U shaped pieces of metal which are bolted to your wall.  There are also two vertical columns as well that you can see, these sit in a special tray in the ground.  The rest of the panels are glued to your walls and  to each with very strong and expensive structural glue, in fact it is the glue that makes up a fair proportion of the cost.   The doors have secure locks on them and bolts into the ground so it is a very secure room, but also a very cosy place with lots of light.

How do I get one?

Glass box installation is a very specialised area and there are only a few companies that do this in the UK.  London Contemporary have installed many glass boxes and can help you not only with the design and build of the glass box but also the interior of it and how it will work with your existing house.  Drop us a line today for more information.