Passive Haus Dundalk

SITE – Small mature garden with many trees , which  required a detailed tree survey to determine  the location , height and spread of each tree , this data had to be inputted into PHPP software to ascertain the impact on the design in terms of solar  gain /shading .

BRIEF-  5 Bed  two storey house  to Certified Passive Standard

DESIGN CONCEPT

Site analysis  ( trees) and sun path determined   the orientation of the house  , the primary aim being to keep north facing windows to a minimum, and locating all the main living spaces to south west to enjoy the optimum benefits of solar gain. A large canopy roof was used to act as a ‘brise soleil’ to counteract overheating but also to provide a covered patio area accessed directly off the kitchen / living spaces .

The design solution is two linear shallow plan blocks one two storey and one single storey , staggered  to create a front entrance between blocks , with car port and garage , porch entrance hall ,kitchen/dining space , playroom , bootroom , cloakroom located at ground level of single storey block ,living room ,  guest bedroom with en-suite  , utility room  and services room are located on  ground floor  of two storey block . The first floor contains master en suite , 3 bedrooms and family bathroom .

The two blocks have monopitched roofs with slate finish on the two storey block & sedum ‘living roof’ on the single storey block . Sedum is a very sustainable  roof finish  as it retards rainwater runoff but also acts as a habitat for birds etc . In addition , it changes colour with the seasons giving a  different appearance to the house at different  times of the year.

Material palette was completed with white self finished  external wall insulation system , and timber cladding  , aluclad triple glazed windows .

DESIGN – PASSIVE HOUSE DESIGN CRITERIA  (calculated using PHPP)

The following performance  targets are required in order to meet the PH Design Criteria;-

• Heating Energy Demand -QH = < 15kWh/(m2a)
• Primary Energy Demand- QP= <120kWh/(m2a) (Includes all necessary energy applications  for heating , cooling , domestic hot water, auxillary electricity, lighting & other electricity uses).
• Building Airtightness – n50<0.6/h
• Excess Temperature Frequency ( overheating ) – <10% /year  ( >25 Deg C)
• Heat Protection –  U<0.15W/m2K (floors , walls , roof )
• Windows – Uw-<0.8W/m2K , Ug- <0.8W/m2K ( g value 50-55%)
• Linear Thermal Bridging – Linear Thermal Bridge Free
• Ventilation –  with min 75% heat recovery  +Electricity demand Max 0.45w/h/m3
• PASSIVE HOUSE PLANNING PACKAGE  (PHPP)

All relevant data is inputted into a spreadsheet  ( PHPP ) which is used as a design tool  that has approximately 600-700  data inputs in order to calculate the Energy Balance and  verify that the energy performance targets are achieved . The design of the house may need to be tweaked & data inputs revised  to achieve the required target figures .

Any design changes made after design sign off (ie window size or location)  may  result in non compliance  as the energy balance is  so finely tuned