What Building Regulations Do You Need to Consider When Planning an Extension to Your Home?

In Ireland, homeowners will sometimes need to seek planning permission in order to extend their home. This is not the case for every sort of building work that might go on, however. If your home and the proposed extension is covered by one of the many exemptions to the usual rules, then you can just get on with the job. However, you should not proceed if you have any doubts about whether or not your project will be covered by one of the exemptions. If you build and then go on to find out that you should have sought permission beforehand, then your building work could be stopped midway through the job leaving you with a mess to sort out, both financial and literal. 

In the worst cases, it is possible that not only will building work be delayed while you seek retrospective planning permission, but you could face fines. It might even be feasible that you are obliged to take down your extension entirely if you have fallen foul of the regulations although – in fairness – such cases tend to be rare. Any application for planning permission you make for alterations to your property needs to be addressed to the Planning Department of your local authority. If you are unsure whether you can proceed without a full planning permission application, then this should be a question that you put in writing to your local Planning Department, too. 

Exceptions Whereby You Don't Generally Need Full Planning Permission

Bear in mind that rule interpretations differ slightly up and down the republic with regards to planning permission for extensions as well as new build homes. What may be okay in one part of the country may need a full plan to be submitted to the local authority elsewhere. The following exceptions, therefore, are only a guide to what you are allowed to build in principle. If your home is in certain location, close to a historic site or the work might impact on a neighbour, then you should seek further clarification with your local Planning Department. That said, you don't always need to seek planning permission for: 

  • Building a front porch. 
  • Constructing boundary walls at the edge of your property. 
  • Building an extension that is under 40 square metres in size. 
  • Building or converting a garage that is under 40 square metres in size. 
  • Adding an oil storage tank or a chimney for a central heating system. 
  • Pouring concrete in your garden to make an area of hard standing, for car parking spaces, for example. 
  • Adding a satellite dish.

It is important to note that you cannot do much at the front of your property unless you seek planning permission. Porches may only be added when they do not exceed two square metres in size and only then if they are more than two metres away from the edge of your property. If a pitched roof is to be added, then you'll also need permission to build it if the roof line will exceed four metres in height. Likewise, the ability to build or convert a garage into a living space is only given freely if it will be located to the side or at the rear of your property. Those at the front which will alter your house's appearance require a full planning application. The same goes for garages that will stand taller than four metres, too. 

If you are planning a fairly run-of-the-mill extension on the side or back of your home and you don't think it will take up more than a 40-square-metre footprint when it is finished, then you can proceed without permission in theory. However, this rule only applies if you will still have an open area – a garden, in effect – that is still larger than 25 square metres in size. In other words, you cannot convert all of the available outdoor space on your property to become part of the house. Some height restrictions come into play, too, but these depend on various factors. Suffice to say that if your intended extension is approaching 40 square metres in size and will be close to the four-metre mark in height that you ought to check if it is allowed under the exemption programme. 

Extensions on Already-Extended Houses

Another important factor to take into consideration when making a design for your house extension is to consider what is the original part of the home and what may have been extended before. Even very well established extensions which might have been up for decades constitute part of the 40-square-metre limit. In other words, if your home has already been extended by yourself or previous owners by 15 square metres, for example, then you can only add a further 25 square metres with any subsequent construction work. If you want to extend more than this, then you will need to obtain permission to do so. 

Building Certification

Like other countries in Europe, building works need to be inspected and checked to ensure they meet the relevant safety regulations. This also means checking that you have not exceeded the rules as laid out, above, in the exemptions to planning permission. Where planning permission has been obtained, a building certificate is also needed to make sure you have stuck to what has been agreed and not gone any further. 

There are two ways to get the necessary sign-off on your extension project once you are in the building phase. The first is the so-called opt-in choice which means you need to assign designer and a certifier. BIY can do this for you. In such cases, the professionals you have assigned must complete the necessary paperwork for the building control management system, or BCMS as it is known, to show that all of the relevant rules, such as fire regulations, have been complied with. 

The other way is to opt out. If you do so, then you must make the necessary declarations, including drawn plans, to building control yourself. Sometimes a building contractor will help you with this, but the legal ramifications of any errors fall on the homeowner in such circumstances. Most people prefer to opt-in, understandably. 

Bear in mind that at BIY, we don't just come up with architectural plans and structural designs that you can use to submit a planning permission request with. We guide you along every step of the way of an extension project, from the design and planning stage, right through to the construction and building regulations control phase. We can even help with the interior design once your extension is built! Read on to find out more about the rules regarding house extensions in Ireland. 

Call BIY to find out how we can get your extension project up and running!