Category Archives: Design

Foundation (Services)

Plumbing Services

A few notes that may be helpful to the self builder when planning the services such as sink waste, cold/hot water feeds, toilet services. The layout of the foundation services necessitates the early planning of bathroom layouts and even the choice of toilets and shower outlets before the floor slab is poured.

Foundation
Foundation Services-White pipes are electrical services.

We visited a local bathroom showroom and we were informed that there are a few different types of toilet systems and they require a different pipe outlet location in the floor to ensure that they will fit. One has also to be sure that the layout of the bathrooms and toilets are what you want before the slab is poured.

For the shower outlets one has to decide between the use of trays or a walk in that is tiled flush with the floor or other finish. This will necessitate different floor slab preparations.

Another factor to keep in mind is that showers or sinks that are lightly used may dry out in the pipe trap resulting in unwelcome smells. I am trying to locate a unit with a larger water trap.

For sink outlets waste pipes it is beneficial to have these mounted in the walls so that different arrangements can be facilitated later on. This necessitates the slab pipework being brought up in the centre of the partition or in the service cavity. I have tried to keep all these inside the airtight membrane.

Kitchen Services

These need a special mention as one has to consider a duct for power cables if a kitchen island is used, water drain outlets for dishwasher etc and a cold water feed for a sink. It is practical to have the water main feed coming into the kitchen first before branching to other locations around the house. (This is more than likely the place one expects to switch the supply on/off) . Consider the grease trap outlet location also as they are substantial in size.

Electrical Services

In relation to electrical cables entering and leaving the house one needs to plan for cable ducts to garden lighting, main electrical supply (using special red ducting), rainwater harvesting cables, power for central vacuum unit if mounted outside the house, telephone line, broadband cables, power for outside shed if applicable, control wiring for services in plant room if situated outside, CCTV/alarm cables if applicable or a plan for these. I feel it is better to put the ducts in now as any unplanned cable changes in the future will affect the fabric of the building. My preference was to use a single 40mm duct for each cable with large sweeping bends for the electrical services. I feel it will be easier to ensure an airtight/rodent/insect seal with heat-shrink tubing on each duct.

Foundation
Foundation Services Layout

 

Ducts

Separate 40mm ducts for each electrical service.

HRV Drip

The HRV unit may also need a water condensation drip outlet. For this I plan to use a half inch heavy duty pipe that will go outside rather than plumbing it into the sewerage outlet.

Garden Water Supply

Because we plan to use a gravity based system the garden taps will be fed from inside the house using a 1/2 inch or 1/4 inch pipe installed in the foundation. One will feed either side of the garden.

Central Vacuum System

If this is being installed a special flexible PVC duct is required if the unit is situated outside the house.

Vcuum
Vacuum duct if placing a central vacuum outside

Performance Standard -Setting the Standard

The passive house software allows one to set your own performance standard by selecting how much energy (oil/gas/electricity) one wants to use to heat the building.

For example current Irish house builds that comply with today’s standard 2014 are estimated to use 100watts per m2 (subjective). The passive house standard if one goes for certification uses 10w per m2 (objective).

The real benefit for using the PHPP software is that the performance approach can be set by the home user. For example if I want to reduce my energy consumption to 1.5 litres of oil per m2 of the house size then I can set the software to a maximum of 15kwh per m2 for the year while maintaining a temperature of 20 degrees Celsius.

In a typical 3 bedroom house with an area of 100m2 the oil usage would be 150 litres a year.  With the PHPP performance software one can set the number of litres of oil (or gas etc) per year that your residential or commercial property will use to within a small margin of error. In other words you select the performance value of your build.

In summary the PHPP software takes into account your comfort and health (temperature and oxygen levels)  by removing high CO2 levels and VOCs and providing an even temperature throughout the house.

A Performance Standard

The Performance Standard

A performance standard is objective (quantitative) . One calculates the energy performance using software called the Passive House Institute planning package (PHPP). It calculates the energy gains and losses. Energy values for example are calculated from the number of people in the house, the solar gain, appliances, all types of losses such as the diameter of copper pipes feeding the hot water taps etc. This tool allows one to create a design for a new build or a renovation where the energy use can be quantified and set by the occupant.

Other solutions for managing building energy usage are in the majority rating systems. A rating system is subjective (nobody knows for sure how efficient it is or how much energy will be used). In Ireland the system is called BER (Building Energy Rating). In England they have BREEAM.

The Irish rating system is weighted towards adding on features such as a porch, solar panels, a heat pump etc., in order to get a high BER rating and it is subjective. One BER assessor may deem it an C2 and another a C3.

The passive house approach primarily aims to reduce and measure your energy consumption and only then do you add features such as solar panels or other heating systems.

While the two approaches exist the BER one is mandatory. What this means is that you could build a house to an energy performance standard that uses the lowest amount of energy in the world and fail to get the current Irish required BER rating.

My interest is the performance approach (using the passive house energy balancing software called PHPP) to design and build the house. As the old/new saying goes “if you can measure it you can manage it“.

A SELF BUILD PASSIVE HOUSE

Self Build Blog

With this passive house self build I aim to design the simplest and most reliable method of providing Lighting, Power and Heating with an emphasis on the life cycle cost (maintenance, repair and health) . The designs will also try to keep things simple. I will explore:

• Solar Water Heating Systems,

• Solar PV,

• Led Lighting,

• Wiring Systems,

• CCTV,

• Water Storage Systems,

• Water Stratification technology and

• Building heating.

• Rainwater Harvesting

I hope to find novel ways of simplifying a self Build that can be used for those who want to build to a performance standard.