Renovating
Ask an Expert: What Do I Need to Know About MEP Before I Build?
Mechanical, electrical and plumbing services (MEP) need to be considered at the planning stage of any successful residential project
MEP stands for mechanical, electrical and plumbing services. It might not be something you’ve heard of before, but if you’re planning a renovation, extension or new build, it’s something you definitely need to come to terms with. In relation to your home, it will refer to such things as heating systems, water supply and electrical plans and, more recently, might include energy-efficient and environmental systems (such as rainwater collectors or geothermal heat source pumps).
At the commercial and industrial scale, MEP is so vital that nothing can go ahead without a detailed specification, but with residential design, it’s often completely left out of the planning process, which might mean that some appliances or finishes a homeowner might want down the line simply aren’t possible because of poor planning.
It’s easy to assume the builder you’re working with has the same vision as you, and likewise a builder can end up making presumptions about a homeowner’s wishes. That’s why it’s so important to have a thorough discussion and proper documentation of your desired MEP services. Here’s a little introduction to what you should know.
At the commercial and industrial scale, MEP is so vital that nothing can go ahead without a detailed specification, but with residential design, it’s often completely left out of the planning process, which might mean that some appliances or finishes a homeowner might want down the line simply aren’t possible because of poor planning.
It’s easy to assume the builder you’re working with has the same vision as you, and likewise a builder can end up making presumptions about a homeowner’s wishes. That’s why it’s so important to have a thorough discussion and proper documentation of your desired MEP services. Here’s a little introduction to what you should know.
Don’t underestimate the importance of MEP
Some might think what’s been said here seems obvious – of course you have to specify these details, otherwise how will the contractor know what to build? Others may point out that this is all well and good in theory, but the original specification will undoubtedly change as the project progresses.
However, the very fact that severe issues still arise shows that many people aren’t paying enough attention to MEP at the planning stage, or perhaps that sometimes homeowners and professionals just aren’t quite on the same page. And while specifications can undoubtedly change, at least if you and your builder are in accord from the start, hopefully any changes won’t be wildly different from the original plan.
Some might think what’s been said here seems obvious – of course you have to specify these details, otherwise how will the contractor know what to build? Others may point out that this is all well and good in theory, but the original specification will undoubtedly change as the project progresses.
However, the very fact that severe issues still arise shows that many people aren’t paying enough attention to MEP at the planning stage, or perhaps that sometimes homeowners and professionals just aren’t quite on the same page. And while specifications can undoubtedly change, at least if you and your builder are in accord from the start, hopefully any changes won’t be wildly different from the original plan.
Be more thorough with certain rooms
There will be parts of the project that won’t require much MEP specification (bedrooms, for example) and there will be areas that will benefit from very specific planning (a high-tech living room or luxury bathroom, for example). To achieve a beautiful, seamless finish to these areas, it’s key that you map them out with precision from the start.
There will be parts of the project that won’t require much MEP specification (bedrooms, for example) and there will be areas that will benefit from very specific planning (a high-tech living room or luxury bathroom, for example). To achieve a beautiful, seamless finish to these areas, it’s key that you map them out with precision from the start.
Get to grips with mechanical services
Mechanical is quite a general term, but it mostly covers heating. It’s important to decide the type of heating you want before any major works begin. Both underfloor and over-floor heating will affect subfloor construction and finished floor levels, and the routing for underfloor heating will need to be considered. Some contemporary designer radiators will need special consideration, with details of where the flow and return are in relation to each other and exactly how it’s hung.
Any good heating engineer will be able to calculate the U-values (a measure of heat loss in a building element, such as a floor or window), and BTU (British Thermal Unit, or heat output –basically, how much radiator power you need) requirements for the property and recommend a system that will meet them. Reputable building firms will have at least one heating engineer in the ranks, but trying to source a heating engineer yourself can get expensive.
Mechanical is quite a general term, but it mostly covers heating. It’s important to decide the type of heating you want before any major works begin. Both underfloor and over-floor heating will affect subfloor construction and finished floor levels, and the routing for underfloor heating will need to be considered. Some contemporary designer radiators will need special consideration, with details of where the flow and return are in relation to each other and exactly how it’s hung.
Any good heating engineer will be able to calculate the U-values (a measure of heat loss in a building element, such as a floor or window), and BTU (British Thermal Unit, or heat output –basically, how much radiator power you need) requirements for the property and recommend a system that will meet them. Reputable building firms will have at least one heating engineer in the ranks, but trying to source a heating engineer yourself can get expensive.
Work out electrical services
There are so many different ways to set out your electrics. What one person considers to be enough sockets might be far too few for another, and the correct height for a light switch will probably be different for a 6ft 4in-tall person than for someone who’s 5ft 3in. Similarly, different electrical appliances will require different cables and outlets, and where those outlets are might determine where you can mount your gadgets, and if you want all the wires to be hidden in the wall… well, you can see how important it is to decide what you want early on.
It’s worth noting that if you’re going for a renovation with a high electrical specification (very good-quality machines and light fittings), you may need to upgrade your cables and fuses (from a 16mm cable and 60amp fuse to a 25mm cable and 100amp fuse). Again, this might sound like jargon, but your builder will know what you mean if you discuss it.
Check out a beginner’s guide to LED lighting
There are so many different ways to set out your electrics. What one person considers to be enough sockets might be far too few for another, and the correct height for a light switch will probably be different for a 6ft 4in-tall person than for someone who’s 5ft 3in. Similarly, different electrical appliances will require different cables and outlets, and where those outlets are might determine where you can mount your gadgets, and if you want all the wires to be hidden in the wall… well, you can see how important it is to decide what you want early on.
It’s worth noting that if you’re going for a renovation with a high electrical specification (very good-quality machines and light fittings), you may need to upgrade your cables and fuses (from a 16mm cable and 60amp fuse to a 25mm cable and 100amp fuse). Again, this might sound like jargon, but your builder will know what you mean if you discuss it.
Check out a beginner’s guide to LED lighting
Address plumbing services
Final specifications of plumbing need to be decided from the outset, too. The water outlets in kitchens and bathrooms need to be fed by the appropriate system, or you could find your shower running cold the moment the kitchen tap is turned on.
For example, a large country home may need two 30kW combi boilers and a 300 litre unvented cylinder. The size of your pipes will be determined by the outlets you intend to install. Don’t worry if this all sounds a little alien, it’s just something to bear in mind to discuss with your builder.
Final specifications of plumbing need to be decided from the outset, too. The water outlets in kitchens and bathrooms need to be fed by the appropriate system, or you could find your shower running cold the moment the kitchen tap is turned on.
For example, a large country home may need two 30kW combi boilers and a 300 litre unvented cylinder. The size of your pipes will be determined by the outlets you intend to install. Don’t worry if this all sounds a little alien, it’s just something to bear in mind to discuss with your builder.
Ensure adequate documentation
In industrial projects or even in large residential developments, MEP can be mapped by putting very precise data into a computer program and producing high-resolution 3D CAD drawings, with all services colour-coded and digitally superimposed into the building. For a slightly more modest residential project, this probably won’t prove cost effective.
What you will need, however, is thorough documentation. Here’s how to get it:
In industrial projects or even in large residential developments, MEP can be mapped by putting very precise data into a computer program and producing high-resolution 3D CAD drawings, with all services colour-coded and digitally superimposed into the building. For a slightly more modest residential project, this probably won’t prove cost effective.
What you will need, however, is thorough documentation. Here’s how to get it:
1 Choose your specific appliances
Once you’ve decided on the layout of your rooms, and have all your appliances selected – are you going for subtle LED downlighting on the staircase? Or perhaps a waterfall shower in the bathroom? – it’s time to get planning.
All of the appliances you’ve selected will have an installation specification detailing their electrical and plumbing requirements.
Once you’ve decided on the layout of your rooms, and have all your appliances selected – are you going for subtle LED downlighting on the staircase? Or perhaps a waterfall shower in the bathroom? – it’s time to get planning.
All of the appliances you’ve selected will have an installation specification detailing their electrical and plumbing requirements.
2 Produce detailed plans
Once you’ve got all of the information for your various appliances and systems, it’s time to start producing plans that map out exactly what each room will require. These need to be very technical, so work with a professional at this stage. The more appliances there are in a given area, the more detailed the plans will need to be to ensure they can be followed precisely by an electrician or plumber.
These plans should be produced with skilled specialists, so the electrician should be involved in the electrical plans, for example. He or she will be able to study the main architectural plans and specifications, and explain how best to run cables, pipes and other services in such a way as to get the best finish, both functionally and aesthetically. Working with larger building firms will give you access to a wide variety of expertise.
These plans will then be added to the main set of architectural plans to give a thorough overview of everything required by the project.
Get expert tips on how to hire the right builder for your project
Once you’ve got all of the information for your various appliances and systems, it’s time to start producing plans that map out exactly what each room will require. These need to be very technical, so work with a professional at this stage. The more appliances there are in a given area, the more detailed the plans will need to be to ensure they can be followed precisely by an electrician or plumber.
These plans should be produced with skilled specialists, so the electrician should be involved in the electrical plans, for example. He or she will be able to study the main architectural plans and specifications, and explain how best to run cables, pipes and other services in such a way as to get the best finish, both functionally and aesthetically. Working with larger building firms will give you access to a wide variety of expertise.
These plans will then be added to the main set of architectural plans to give a thorough overview of everything required by the project.
Get expert tips on how to hire the right builder for your project
Be thorough
It’s vital to think about every inch of the project and find the best solutions for you. Consider which MEP services are required for your specific needs, and fulfil those requirements in a smart way. Doing this from the planning stage will ensure the physical building process will be an experience you can enjoy, and that the finished home meets your original vision.
TELL US…
Do you have any experience with planning MEP services? Please share your thoughts and advice in the Comments below.
It’s vital to think about every inch of the project and find the best solutions for you. Consider which MEP services are required for your specific needs, and fulfil those requirements in a smart way. Doing this from the planning stage will ensure the physical building process will be an experience you can enjoy, and that the finished home meets your original vision.
TELL US…
Do you have any experience with planning MEP services? Please share your thoughts and advice in the Comments below.
The most common cause of problems arising during the build is inadequate planning. Without proper discussion, presumptions can be made, and if you haven’t even talked about these things with a builder let alone documented them, it’s easy for mistakes to be made.
Mistakes result in extra time for the builder, extra cost to the client, and probably not the best finish. A good builder knows that true quality and a beautiful finish can only be achieved with almost clinically perfect planning. This must include a full MEP specification.