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Dublin: 14°C Friday 19 August 2022

You want to extend but you don't have planning? No problem...

Not quite – but we do discuss how you can extend without planning permission.

IT’S A TRUTH universally acknowledged that going for planning permission can be a bit of a nightmare.

All you want in the world is a little extra space in your house – for growing kids, or a conservatory out the back or that James Bond style gadget room you’ve had your heart set on forever. 

Something to aspire to - the Enid A Haupt Conservatory Source: Princess Ruto via Flickr/CC

The good news is – you can extend without planning permission. The bad news is that just like everything else, there are terms and conditions to adhere to.

We spoke to architect Mo Zainal about the regulations around building without planning permission.

Foundation Source: via Flickr/CC

What are the advantages to building without planning permission? 

One of the main reasons people want to build without planning permission is the amount of time that’s involved.  Planning applications cost both time and money – it can take up to 12 weeks to get permission (up to 8 weeks for notice on decision to grant and an additional 4 weeks before permission is finally granted). The requirement for planning application documents including site layouts, plans, elevations etc which will also require additional time and expense.

You have to wait three months to get permission, before you can even do anything. Sometimes it doesn’t even get approved and then you’ve had three months of work that are wasted so it is quite  a long process, so if you can avoid it, it’s the best thing to do.

So there’s the whole planning side of things, but also with the new building control regulations, anything greater than 40 sq metres, if you’re doing an extension, you will need to appoint an assigned certifier.

An assigned certifier is a registered architect, an engineer or a quantity surveyor and basically what they have to do is lodge a whole collection of documents with the BCAR (the building control authority) and it takes a lot of work, disclaiming all the information and lodging the application and a commencement notice, and that all adds to the cost. It is something that’s quite new, and people are only just starting to get their heads around it. It’s something else to consider.

This – the assigned certifier obligation – comes from all sorts of regulations – fire, disabled access. It throws up all sorts of onerous obligations.

What are the disadvantages to the restrictions?

Basically you’re limited in the size and not being able to build to the side or front of the property. The extension has to be under 40 square metres and it’s not meant to be seen from the front. So you have to restrict it to the back of the house. And if you have a previous extension that has to be included in the calculations. So if there’s an old extension that’s already there, you have to include that in within the 40 sq metres.

However, I would say – don’t look at restriction as a disadvantage. Sometimes small is good – it has cost implications, it maximises your garden space. There can be various advantages for keeping it small. And being able to do without planning permission is an advantage.

Ideally if you can get away without planning permission, I’d definitely recommend it.

Source: amslerPIX via Flickr/CC

What are the regulations regarding what you can do without planning?

You need to be qualified as an exempted development. There are a number of restrictions to qualify -
  • Size restriction - extension must not exceed 40 sq metres (this includes previous extensions built after 1964) and in addition to this, no more than 20 sq metres of this can be built on upper floors for terrace/semi-detached houses and no more than 12 sq metres on upper floors for terrace/semi-detached houses.
  • Height restrictions - Walls are not to exceed the height of the existing rear wall (or side walls if rear wall is a gabled wall) and roofs not to exceed the height of the existing roofs.
  • Open space - you need to maintain at least 25 sq metres open space to the rear.
  • Set backs - the upper floor extension shall be no less than 2 metres from party boundaries
  • Windows - you need to maintain a minimum distance from the boundaries they face – 1 metre for ground floor windows and 11 metres for upper floor windows.

What new regulations are in place?

New building control regulations (BCAR) now state that all works that require planning permission must also lodge a commencement notice with the building control authority. And all extensions greater than 40 sq metres have additional requirements:
  • Appointment of Assigned Certifier (Registered Architect, Surveyor, Chartered Engineer)
  • Certificates of compliance at both commencement and completion
  • Inspection plans
  • Drawings for building control purposes

Complying with all the above will require a significant amount of work and mean additional professional fees for the the extra services. So there’s additional costs involved that can be avoided by keeping the development smaller.

(You can find out more here:

Source: Grand Canyon NPS via Flickr/CC

What other requirements are there?

All extensions regardless of whether or not they require planning permission will need to comply with the procedures set out in the Safety, Health and Welfare (Construction) Regulations 2013.

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This includes appointing project supervisors during both the design and construction stages who will need to follow through their stated responsibilities and compile the necessary documentation.

Compliance with the above is required for all projects that will take more than 30 days to complete or involves more than one contractor or entails a particular risk. Generally most extensions will fall into one or more of these categories.

Do people tend to use an architect for these smaller extensions and if they don’t, should they?

A lot of times, people don’t. There’s a reason why architects have been trained to integrate the various aspects of design and function, where the light comes in, all of that.

You know, it takes a while to go through the various options and really only an architect can appreciate the time that’s required to arrive at a solution that’s going to work. In the end it’s going to be there forever. So you want to make sure that you get it right. It’s worth spending the time and effort to make sure that the final plan is right because once you go ahead there’s no going back.

I would recommend an architect. It’s not a huge expense in terms of the long-term investment, it’s well worth it. An architect can also advise on thermal performance and things like that.

What are the most common extensions people do? 

The most common are extensions are extending the kitchen or living area. And in a lot of cases, even though it mightn’t seem like it – it’s all part of an entire ground floor refurbishment. Say you’re adding on 20 sqm, you’re actually reconfiguring the entire space downstairs and it’s important not just to focus on that extra extension and to look on the whole of the ground floor as one opportunity. (This is where using an architect is particularly helpful.)

Don’t think that that 40sq metres is a limit and a negative. It forces you to look at the rest of the space as well. Because you’re forcing yourself to look at what’s there and making use of what’s there, you’re making sure that your budget is kept quite low – because when people do big extensions at the back, they ignore what’s existing and it ends up not being integrated with the rest of the house as a whole.

Tips for building without planning permission

  • Keep it under 40 sq metres
  • use an architect
  • consider the layout of the whole house – not just the extension itself
  • extension can’t be seen from the front

Read: 100-year-old house? Here are a few tips for an energy-efficient upgrade

Also: How an amazing retrofit improved this Irish home’s energy rating by 90%

About the author:

Edel Corrigan

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