Week 6 - Passivhaus Design Blog

Passive Design

 Regulations on building 

One thing I thought would be important to know is the building regulations surrounding the installation of an MHRV system. What should be used to pump the air around the house, how should they be layed out and should they be insulated. Below is an extract taken directly from the Technical Guidance document F - Ventilation, which explains how MHRV system ducting should be installed.

"The use of rigid ductwork improves robustness and reduces risks of leaks. Use of flexible ductwork should be avoided and should only be used in very short lengths and mainly to connect rigid ductwork to diffusers/units or to overcome particular obstructions. All flexible ducting should be pulled taut to minimize system resistance. No peaks or troughs should occur in ductwork. The cross sectional area of the ductwork Diagram 2a: Mechanical ventilation with heat recovery – House Diagram 2c: Natural Ventilation with intermittent fans mechanical extract - House 14 should be maintained throughout the full length of the duct run." 

Fire safety

For my design I have decided to go with semi-detached homes. I know when it comes to the internal design and floor plan layout the aim is to ensure that a satisfactory standard of means of escape is provided for persons in the event of fire in a building. Which is why I have included a front and back door on my home so that occupants can exit safely no matter what side of the building the fire occurs. Below shows fire exit routes that should be observed by the occupants when they enter the home.

I also wanted to know, in the evident their was an internal fire, what is the regulations surrounding the fire reaching the other house that is attached? they share one wall so what should be taken into consideration to prevent the fire spreading and stop the structure collapsing? Below is a section of the Technical Guidence document B - fire safety (2006) explaining how to treat this situation.

"Internal fire spread B3 (structure).

(1) A building shall be so designed and constructed that, in the event of fire, its stability will be maintained for a reasonable period. 

(2) (a) A wall common to two or more buildings shall be so designed and constructed that it offers adequate resistance to the spread of fire between those buildings. 

(b) A building shall be sub-divided with fire resisting construction where this is necessary to inhibit the spread of fire within the building. 

(3) A building shall be so designed and constructed that the unseen spread of fire and smoke within concealed spaces in its structure or fabric is inhibited where necessary. 

(4) For the purposes of sub-paragraph 2(a), a house in a terrace and a semi-detached house are each to be treated as being a separate building."

With my building being a block construction the structural integrity of the building will last much longer then that of a timber frame house. The shared wall of the two houses should be lined with a fire proofing membrane to stop the flames entering the cavity and spreading to the other home. It also states that the semi-detached house should be treated as separate buildings so the shared wall between them should reflect this in its construction.

Windows and Fenestration

Fenestration is the term used to describe the arrangement of the windows on the façade of a building. Fenestration is a combination of the pattern of windows on the façade of the building, subdivisions of the window, proportion of panes, recessing and projection of the windows. While the technical performance of windows is very important, as in how energy efficient they are, it is also important not to lose sight of the aesthetic role of glazing in building design.

For my building design the south side of the building is the one that contains the most glazing, so I wanted to ensure the windows did not look like they were just thrown is but align with each other so that the aesthetic look of the building was not lost when I am trying to maximise light in the home. The windows all align perfectly with each other so that it appears symmetrical, and the top of the windows are in line with the top of the door frame.

Site Map - finalizing layout

From my above proposed layout I made on PowerPoint so it could be color-coded, you can see how I plan to divide up the public, private and semi-private. The light green at the back of the houses represents each dwellings individual lawn or back garden space which is private, along with the dark green which is a path to the back of the dwelling. Public areas are the likes of the road and footpath which are in grey above, and semi private areas is the unmarked grass areas surrounding the property which will more or less be inaccessible due to shrubbery. Parking for the property is marked in yellow and the dwelling itself is in blue. In my Urban Design portfolio I go into allot greater detail as to why I have laid my site out this way and all the different considerations I made to come up with my layout.