Passive Design

When you embark on building a new house or renovating or adding an extension to your existing house you are confronted with a myriad of decisions.

Most of these are cosmetic such as kitchens,sanitary ware paint colours etc.

In the confusion it is sometimes understandable to lose focus on the building fabric and construction.

This is the way of most new builds and extensions and renovations.

Passive Homes Ltd. have the knowledge and experience to take our clients through the process as painlessly as possible.

We not only build your house,renovation or extension to the highest levels of construction we also will finish out your house from start to finish.

We look at each element such as , thermal mass floor insulation attic or crawlspace insulation, wall insulation, basement insulation and design these elements to meet passive standards.

With this and the elimination of cold bridges we ensure you get a house that is energy passive.

The result is a building that is sustainable with excellent comfort and air quality.

It's the ultimate green dream home.

To achieve the required results the design process must follow very defined principles.

The process can be varied but the fundamentals must be maintained.

These fundamentals are

• Thermal Bridging

• Air tightness

• Heat recovery

• Insulation

Passive solar

Here is a list of the key elements in any design process

• Client Brief:

This is the initial meeting with the client to understand from the client their needs and to explain what is involved in the process from house design to insulation to windows to thermal bridging.

In many cases clients have excellent knowledge of what is involved but some clients will have to be briefed on each part of the building process and the house design process.

In many ways the Client brief is the most important part of the whole process as it will outline the benefits of good house passive house design such as energy savings etc.

• Site visits:

The site visit is very important to understand the orientation of the site with a view to maximising solar gain. It will also determine if trees or other structures overshadow the proposed home. When visiting the site both the designer will outline the best orientation to the clients.

• Sketch Design

The designer will either design the house or look at predetermined designs and alter same where necessary to ensure the optimum passive design.

• Detailed Design

PHPP software to evaluate and refine the build process.

At this stage the nitty gritty of the design process will take place to ensure that the standards for all areas of the house are met.

In many cases this will determine the insulation types the junction details and the type of build elements to be used and the level of air tightness.

The thermal bridge junctions will be modelled by computer software and the results installed in the PHPP software.

The trade off of build elements will take place to get the best fit and best price.

• The Build process

The build process is putting all the details into action.

The build process determines the type of construction method either using traditional construction or passive precast solutions.

It requires a totally different approach from normal site operations as each construction phase will be checked and tested to ensure it meets the design requirements.

Short cuts and poor workmanship are a disaster to passive house building as you can never bury mistakes and testing such as air pressure tests and thermal imaging will show any weakness in the build process.

All elements are recorded photographed and signed off by the site supervisor.

• Post Construction Testing.

This will determine the quality of the workmanship and the design.

Normally two tests are required by independent testing authorities. Firstly the air test will determine the air changes and secondly the thermal test will determine if thermal bridging is present.

As you can see the built process is really the appliance of science in building.

Gone are the days when each trade does his own thing and the plasterer covers it up.

With passive building the building must meet precise measurements the material use, the installation and the workmanship must be 100% all the time.

Each member of the building team must be 100% behind the process and if any doubts are raised by any team member the whole team must take them on board.

Once the testing is certified the home owner will receive a certificate from the Passivhaus Institute.

The one obvious question arises at this stage. Is it more expensive?

The answer is no

It’s the same as an ordinary house in terms of cost. Certain elements are more expensive such as insulation and windows and testing but are offset by no heating system installation costs.Of course the end result is a home which has no heating bills which is exceptionally comfortable and which is healthy to live in.

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