Browse Forums Eco Living 1 Oct 15, 2017 4:43 pm Hi All, Anyone able to clear up my current understanding of glazing to "floor" ratio? Questions - Does "floor space" mean the entire house or just the rooms where the north glazing windows will be. Does this area also exclude wet areas and garage? - If you have come across solar passive design principals for a "U" shaped house could you please point me to them. I've attached a picture to help illustrate what we're working with. I'm just not sure if i should treat the two sections in the red boxes as separate.. or if my calculations should be for all my walls that face north combined (over the total floor size of the house). Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Thanks in advance. Re: Glazing to Mass ratio for a U shaped house 2Oct 16, 2017 5:36 am Just some basics Your house is a volume protected by walls and ceilings.(preventing heat gain/loss) and providing weatherproofing The most efficient volume is a sphere because it has least surface area/volume The most efficient floor plan is a circle because it has least walls/area. The more you get away from circle the more inefficient your floor plan will be Square is less efficient than circle Rectangle is less efficient than square Your (U) plan is less efficient than rectangle Vertically(look at your elevation), single storey(rectangle) is less efficient than two storey (square) To answer your question, all of your floor areas must be included in calculations Foremost Building Expert in Australia,assisting with building problems/disputes, building stage inspections,pre-contract review advice for peace of mind 200 blogs http://www.buildingexpert.net.au/blog Re: Glazing to Mass ratio for a U shaped house 3Oct 16, 2017 1:11 pm Hi building-expert, Thankyou for the info. Will this mean some areas (those facing north) of my home will overheat but over time the temperature will roughly even out throughout the house? Re: Glazing to Mass ratio for a U shaped house 4Oct 16, 2017 6:32 pm When calculating thermal mass what has direct contact with sunlight... do you take a snapshot at say noon around june 20th? Or do you assess it as the general area where light would hit over the entire day? Re: Glazing to Mass ratio for a U shaped house 5Oct 16, 2017 7:17 pm I believe starting with a shadow diagrams will help a lot here. From what I see, the northern part of the building will be dropping almost constant shadow on to the courtyard area and southern part of the building. Having wide covered alfresco at the north is an issue as it will be blocking direct sunlight during winter, too. Ideally, you would need covered area to be not wider than extended eaves per your passive solar eaves calculation (see http://www.yourhome.gov.au/passive-design/shading) I would suggest to have a patio with retractable roof for the rest of the patio roof area. Hope it helps. Re: Glazing to Mass ratio for a U shaped house 6Oct 17, 2017 11:11 pm alexp79 I believe starting with a shadow diagrams will help a lot here. From what I see, the northern part of the building will be dropping almost constant shadow on to the courtyard area and southern part of the building. Having wide covered alfresco at the north is an issue as it will be blocking direct sunlight during winter, too. Ideally, you would need covered area to be not wider than extended eaves per your passive solar eaves calculation (see http://www.yourhome.gov.au/passive-design/shading) I would suggest to have a patio with retractable roof for the rest of the patio roof area. Hope it helps. Hi alexp79, Firstly, thank you for taking the time to read my question I was also worried about shading so I spent a few nights learning how to use sketchup. I've decided to cut out a section of the alfresco roof as seen in the image below. I haven't seen anyone cut into the roof like this so maybe i'm a little crazy? My plan is to install some sort of adjustable awning/shade to cover up the whole during summer time or when i need it. Light now penetrates deeper into the rooms but i'm not confident on how to calculate the glazing to mass ratio (more specifically trying to find out how much extra thermal mass i need). If taking "building-experts" advice that the floor space is for the whole building... then i'm at around 10%. But ifs its just for the living + kitchen then i'm hitting (10.7sqm glazing verse the floor space around 57.18sqm).. 18.7%. This is higher than the 14% suggesting in yourhome.gov.au website. so.... will this room overheat? This picture is for 12PM on June 20th and geo located on our block. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ As for the inner courtyard i was hoping our family would use it mostly in spring & summer times. In winter, yes it does get shadowed but i'm glad that light still comes into the bedrooms. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Glazing to Mass ratio for a U shaped house 7Oct 18, 2017 12:58 am Take a look at Vergola's or Lourvetec - you will probably end up quite well with a similar solution instead of cutting a hole in the alfresco - I don't think structural engineers will allow it that way. I would probably remove alfresco completely and just put in a retractable roofing all the way from the house boundary up to the kitchen - it will look much better this way. You would need to use hip-and-valley type of a roof for your house in this case. You won't be getting much heat in the winter to your bedroom 3 and lounge, but may be this is not the worst thing as it is okay to put bedrooms to the southern side in order to keep them cooler, but do consider investing into a decent heating solution for this area. Also, your thermal mass calcs won't be making much sense over there, too. Do focus on maximising the northern part thermal mass though - I believe you would need to plan to have a concrete slab with tiles or polished concrete over there in order to maximise the mass. I would be also worried about extensive southern wall glazing in your northern area (facing family room) - you will be losing tons of heat through those glass doors over there. Consider double glazing there and reducing glazing dimensions. Rule of the thumb re thermal mass to glazing is 6 to 1 but variations of up to 8 to 1 can be possible. However, your can't count the full northern facing floor area for thermal mass as the window sun will be falling on the floor at certain angle and the flooring beyond this angle won't be hit with the direct sunlight. To understand better, you should be running the calc depending on the length of your eaves/shading and the height of your glazing, to understand what will be the area for thermal mass calcs. By the way, my initial set up (and orientation) was very similar to yours (double storey though), but later I have decided to get rid of the court yard and make the house L-shaped (with very thick horisontal line and very tiny and thin vertical line in L) instead in order to maximise direct sun light to the front yard and to my kitchen and dining area. Re: Glazing to Mass ratio for a U shaped house 8Oct 18, 2017 7:14 am I will check out those companies. I have changed the courtyards sliding doors into 2x french doors. They are currently 2.4m high as i'm not too keen on 2.1m. I asked about double glazing and the cost was pretty big (won't have budget for much else). So now we're planning to go low-e and make do with it.... maybe look at double glazing just all the doors and windows in the main living area at the back of the house... Thanks for your input! This is one of the reasons I decided to go overseas for my double glazed windows. As the builder indicated, he's worked on many upmarket builds, these were the most well… 13 19076 For your reference Performance Labels: Window assemblies in housing, except timber windows, must be labelled so the label can be seen when it is in situ. For timber… 6 7673 You’re on the right track, wire brush in a grinder then a zinc rich epoxy primer then a top coat of some sort, like a waterproofing membrane. Raising the concrete would… 1 7020 |