12 Critical Questions to Consider When Building a House Extension in Ireland

Maybe the plan was to move to a bigger house… however current economic circumstances have removed this option for many people. The next option, and often times the best option, is to look at how to create more space in your existing house.

What sort of space do you need, where do you need it, how should it integrate with the rest of the house, and what impact will it have on the existing house in terms of light, space, comfort, disruption, and value?

Here are 12 critical questions to to consider when planning your house extension project in Ireland:

  1. What sort of space do you need – living room, kitchen, playroom, utility room, downstairs bathroom, home office, open plan kitchen/dining/living room? Consider the long-term issues as well as your immediate problem, and consider how a prospective house buyer might value and appreciate what you are considering.
  2. What are your options in terms of where you can extend, and how suited is this to your space requirements? For example, having an attic conversion as a playroom for small children doesn’t make great sense.
  3. What impact will the extension have on the existing house and garden? Consider how the extension will impact on light within the existing house, for example, and how you will compensate for this.
  4. Do you require planning permission? In Ireland you are allowed to extend by up to 40 sqm (430 sqft) of additional floor area at the back of your house without planning permission, subject to certain conditions.
  5. Do you need an architects input? If the problem is complex with no obvious solution, then a good architect can add real value. On the other hand, with a more straightforward job, an architect is often unnecessary, and a good building contractor or project manager with the relevant expertise should suffice.
  6. What other professionals will you need to involve? Apart from design and planning expertise, for significant structural alterations, it’s always advisable to get a structural engineer to specify the requirements and sign off on the work.
  7. What building standards should the extension be built to? The Irish 2008 Building Regulations Technical Guidance Documents are the minimum requirements for habitable dwellings, including extensions. In particular, Part L is critical from an insulation and energy efficiency perspective. However, minimum insulation requirements are basic, and you really should decide to go well beyond thatto minimise future costs and green taxes.
  8. What method of construction will best suit an extension? The typical options are traditional block built, timber frame, structural insulated panels (SIP’s), and insulated concrete formwork (ICF). They all have advantages and disadvantages for home extension work, but the two commonest options for extensions in Ireland are traditional block built and timber frame. Traditional block built is sadly still a favourite in Ireland and it’s not a coincidence that our domestic heating energy costs are among the highest in Europe.
  9. How do you pick the right contractor? Ultimately, it’s about trust and your ‘gut feel’ that the contractor is a competent honest expert delivering good value for money. Back up your ‘gut feel’ with some simple research.
  10. How long will it take to build a typical extension? Traditional block built extensions completion times are the longest and will be determined by size and weather, but a typical 25 sqm extension is going to take 8-10 weeks on average. A site built timber frame alternative should take about 2 weeks less, while at the other extreme, an off-site built timber or steel frame extension can be completed in as little as 2 weeks.
  11. How much will a home extension cost in Ireland in 2010? This can vary widely, but as a rule of thumb, €140 – €175 (including VAT) per sq ft of external building area is a good estimate for a fully completed traditional block built extension. However, if it’s too good to be true, it usually is. The devil is in the detail, and be careful when comparing.
  12. How will you pay for your extension? In seeking funding for a home extension project, providing you have the means to service the borrowings, you may want to consider a combination of Credit Union and bank/building society to get the necessary funding. Presentation of the project to your lending institution in the right way will help greatly.