Where is the best place to build your dream home?

Expert builder Kieran McCarthy on choosing a site for your house

Flat or gently sloped sites are by far the most efficient in terms of building, excavation, and engineering work. Picture: iStock

Hi Kieran, My wife and I plan to build our home on a section of land on our family farm, but need to decide the best spot. What are the things we must consider?

Does it have to be a flat surface? Some of the land is a hill and can also be rocky. Does this have a big impact for the builder?

Thanks

Peter and Catherine, Dungarvan

Hi, Peter and Catherine. Thank you for this great question. You are fortunate to have family land to build on.

Though you have the potential to set yourself up for idyllic family life in the countryside, you also rightly ask if there are factors that would determine the best and most efficient siting for your new home.

Kieran McCarthy: 'You need safe egress onto the main road, where you will need to be able to see a significant distance up and down.'

The first thing I would consider is access to a roadway. This is important for a variety of reasons. Firstly, you need safe egress onto the main road, where you will need to be able to see a significant distance up and down, in line with the prevailing road speed limit. This is important to ensure driving safety, for you and other road users, and will form a key part of your planning permission.

I would consider various sites, in conjunction with the road access and sight distance. Once you have settled on a suitable road access, I would try and keep a reasonably efficient driveway length beyond this (for budget reasons). Another key factor is the gradient of your driveway.

How will your driveway perform in the winter, when ice and snow are present?

Next on the list is the topography of the field you are considering. Is your site flat or sloped?

Flat or gently sloped sites are by far the most efficient in terms of building, excavation, and engineering work. A flat site involves site clearance, footing excavation, and concrete pouring, or about a week’s work. A sloped site may contain rock or loose clay.

It might require rock breaking or retaining walls and drainage. It may even require specialist foundations ( a raft foundation, piling, or even rock anchoring).

All these specialist engineering considerations cost time (both on site and in the design office) and money. When these foundations are complete, you will be backfilling around the costly foundations and you will have no trace of all the expenditure, apart from the dent in your bank balance and those sleepless nights.

Another consideration is wind shelter. In Ireland, the prevailing wind comes from the southwest, so any shelter you can obtain from surrounding topography is a huge asset. I visualise what a site would be like in the depths of winter in a huge storm and how to site the house appropriately. Land drainage is also a consideration. If the site is on a steep slope or in a valley, surface water may need to be drained away from your new home in times of heavy rainfall and flooding.

In general terms, the simplest house to design has a south- or west-facing rear garden, where you have ample access to afternoon and evening sunlight. Picture: iStock

Though we have considered some of the key engineering and budget-related issues, there are many other factors that need to be borne in mind.

Have you a view from your site and how is this best captured?

What direction does your proposed new house site face?

In general terms, the simplest house to design has a south- or west-facing rear garden, where you have ample access to afternoon and evening sunlight, but there is often a conflict between the best light and the best views.

In the countryside, the lines between the ‘front’ and the ‘back’ of your house become blurred and you orientate your house to balance the light and views and design the house so that this area of sweet spot becomes the private family space, both internally and externally, and the hallway, front door, and car parking are sited elsewhere.

So, many factors to balance here, in terms of design, budget, and engineering, and that is before we even delve into the depths of planning policy.

I would try to sidestep major engineering issues, where possible, as these will place a significant strain on your budget and, when all is said and done, you will never appreciate this expenditure and heartache when they become a distant, underground memory.

• Civil engineer Kieran McCarthy is founder of, and design and build director with, KMC Homes. He is a co-presenter of the RTÉ show, ‘Cheap Irish Houses’.