SUNSLOPE Supporting Considerations

Transcription

1 aw, dj 9/19/17 SUNSLOPE Supporting Considerations General style desiderata elaborated Based on the P&I as outlined in our one-page proposal, here are what we take to be HM s key criteria for residential design with implications for style: 1) Sustainability desiderata - major South-facing roofs at low pitch, suitable for PV or solar hot water 1, either integrated or mounted above - region-appropriate passive solar capacity (sunlight in winter months with thermal mass for absorption inside; mostly blocked in summer to prevent overheating) - significant shared walls (duplex) for efficiency; mostly 2-story (ditto) - buildable using alternative eco-appealing construction techniques and materials, e.g. SIPs (Structural Insulated Panels), ICF (Insulated Concrete Forms), etc., should we choose them 2) Affordability desiderata - relatively simple to build (keep construction costs down) - relatively simple to vary for different size houses (from 1BR to group houses, with 3BR as standard) (keep design costs down) - available adaptable plans from the web (keeping design costs down); and/or - potentially buildable using alternative, less expensive construction techniques and materials, e.g. kits or modules, should we choose them 3) Style & siting desiderata 1 Recent discussions suggest that with significant improvements in PV efficiency, a separate solar hot water system is not the most economical choice: it would be better to have an all-pv system that uses some of its peak production to run electric heat-pump water heaters (see But this is a Sustainability question, and we don t propose to settle it here: roof space is the only issue for now, and since solar hot water takes equal or less roof space for the same amount of hot water, we are good either way. 2

2 - hybridizing our two preferred styles of styles: some degree of continuity with FHA Schematic Design at the same time that some cottage-like, craftsman, or traditional elements are included - design adaptable for different positions in the village: esp. both north and south of the village path - design enables both private outdoor spaces and sociable multi-unit outdoor spaces ( clusters ) The Sunslope Concept 1. Basic section The proposed design starts with a large south-facing, low-pitched roof where PV would be installed. This is the prime roof for the unit and primary motivation for the design. Attached to it on the north side is a smaller roof at the same pitch in the other direction, not as large, making it technically an asymmetrical gable roof. In simple section view, it looks like this: 2. Basic interior layout This roof layout immediately suggests a quite specific internal plan, which seems to be common across nearly all of the plans we have found with this type of roof. It is a story-and-a half layout. Under the lower end of the big roof is the LR and probably DR, with the sloping roof creating a bit of vault above. Under the upper end of the big roof is a half second floor with bedrooms and a bath, over a downstairs kitchen and another BR or study. (This is the basic 3 BR version.) A 3

3 stair rises from the downstairs living/dining space to the second floor, allowing for a balcony overlooking the lower area as well. In section, the concept is this: In floorplan, the concept is something like this: Possible first floor (image 3) ignore garage!! And the deck is TBD just look at the house itself. 4

4 All dimensons are approximate,of course! Again, the main point is just to get a sense of the possible distribution of rooms. (By way of comparison, Amy and Anthony s LR is 21x14.) Possible second floor (image 4) Plans from This unit is 1520 sf. 3. Basic look It s been hard to find existing images online that come close to our image of how good Sunslopes could look like at HM. Here are some drawings by AW and some online images to 5

5 give you a very rough picture none of these is perfect but together should give you some idea. Image 5: A very plain view of a potential duplex (by AW). [Images 11 and 12 below are some possible floor plans for this structure; the chimney would be shared or you could picture it without chimney; the dormer could be larger, doubled, funkier, or omitted entirely in place of skylights or light tubes).] Image 6: A potential side view with more cottagey features (AW) Here are some images from the web, none of which (again, alas) approaches our 6

6 vision for how good these buildings could actually look, but at least they give you some idea of shape and massing. Image 7 Images 3 and 4 are floorplans for this house. As pictured here the roof is steeper than we propose, and the windows and bump-outs probably would have to be rethought and simplified, and who knows about the outside wall materials and colors.. but this gives a good sense of shape at least. Image 8 Starker and bigger, also steeper roof pitch than we picture, but again you get a sense of overall shape and possible dormer (which would probably divide in two, or run across the whole roof, as this looks to be duplex size.) Compare image 5. 7

7 Image 9 We will have more to say about this one below, but for now just note that it is a view from the high side; also the balcony is notable. For more, Inside look Here is one image to get a sense of the feel of the great space. (Again it s hard to find really representative images.) Stairs are presumably off the picture to the right. (Image 10) 8

8 3. Meeting basic desiderata Sustainability: - PV: The driving feature of this design is the big south-facing roof. Our very rough initial caluclations suggest that each units s big south-facing roof would offer about twice the area needed for PV to support all of that unit s electrical use (and this assumes it is all-electric), so that there is major space left over for additional PV for other units, farm use, or return to grid if we are net metering. We can fine-tune the pitch for optimal PV: data from FHA suggest it is about 3-in-12 or 4-in-12 for our region, which (again) is a lower pitch than in the images from the web above. Apparently only about 75% of an actual roof area can be used for panels due to fire dept requirements for firefighter roof access: this is accounted for in our very rough figuring. Also we will want some roof space for dormers, skylights, etc. - Region-appropriate passive solar capacity. South-facing windows in all units, along with possible skylights and dormers, with trellises and porches also possible. We need professional determination of exactly how much window we want for optimal seasonal solar gain (or nongain). Each unit will also have either east- or west-facing windows. - Duplexing: This layout can readily be duplexed with a long shared wall. Using the floor plan above (image 3) and a mirrored version of the same, image 11 gives you a rough idea of how. Notice that I have made some other changes, most notably eliminating the pushed-in entry so as to maximize enclosed space as well as shared wall. 9

9 Image 11 Image 12: possible second floor of simple duplex terrible image, sorry, still have to scan this again --aw 10

10 Duplexes could also be more complexly laid out more interesting visually etc. but also not as simple to build. Images (again using the originals in images 3 and 4) gives you one example (yes, totally, the entry could be redone to make for more shared wall and less wasted undercover space -- what was I thinking?). Image 13: Offset duplex floorplan level 1 11

11 Image 14: Offset duplex floorplan level 2 Image 15: 3D just the masses: - Alternative building techniques and materials: these designs should be fully compatible with alternative building techniques and materials. 12

12 Affordability: - Simple to build: Sunslopes have basically rectangular footprints (some of the fancy bumpouts on the sample floorplans will have to be pushed back, or made available as add-ons) with broad low-slope simple roofs. - Simple to vary: We would have to work out versions of this design for various sized residences. Most of the designs here are for 3BR. However, a 2BR version should be possible by moving the kitchen into the great room space while narrowing the whole unit, with a small BR or study downstairs and a single somewhat larger BR upstairs. Online we have found decent floorplans for both 2BR and 1BR versions. - Available adaptable plans: yes. There are a wide range of fairly similar designs available as pre-designed plans online, from companies that also work with clients to customize plans. Standard prices for construction-ready plans bought as-is average around $1000; standard prices for adapting them are less predictable but seem to be roughly around $ Of course we are looking at multiple sizes as well. It is hard to predict total design costs!! By contrast, though, the Design Development and Construction Drawing phase with FHA (to be fair, this included the Common House) was around $90, Alternative financially appealing construction techniques and materials: Again, these designs should be fully compatible with alternative building techniques and materials. Style and feel: - Hybridizing our two preferred styles: Sunslope retains the simple and clean lines of FHA s modernism, but at the same time moves to a more traditional roof style (gable, though asymmetrical). Detailing with porch, trellis, window boxes, etc. can give more of a cottage feel also (as in image 6); and dormers are possible too. Along the lines of traditional, we would also note that the closest Sunslope comes to a traditional roofline is to the so-called Saltbox style. A saltbox house is a traditional New England style of house with a long, pitched roof that slopes down to the back, generally a wooden frame house. A saltbox has just one story in the back and two stories in the front. The flat front and central chimney are recognizable features, but the asymmetry of the unequal sides and the long, low rear roof line are the most distinctive features of a saltbox, which takes its name from its resemblance to a wooden lidded box in which salt was once kept. The traditional Saltbox also has a 10-in-12 or 12-in-12 sloped roof, its front typically on the high 13

13 (2 story) side, and its long axis parallel to the front and back rather than the sides. Sunslope, again, has much less steep pitch, can readily front on the low side (making for a more humanscaled roof edge), and may be more square in floorplan. Still, we believe with its echo of a saltbox but in a modern and solar-adapted form, it is not only more functional but has a distinctive air to it as opposed to a plain gable. - Design adaptable for different positions in the village, especially both north and south of the village path. Yes, but this is complicated. So far the images have been for layouts that front on the low (South) side on the units. This is natural for units on the north side of the main path. In this case, LR and DR face the public spaces (as well as east or west depending on which side of the duplex they occupy) and BRs are a bit more private (a concern at least downstairs). The other half of our units will be on the south side of the path. We do not want to flip the layouts over so that their main roofs slope north after all the point is to have the main roof always maximize PV opportunity (they are Sunslopes after all) ie. face south. One concern about the FHA site design was that they did flip their units over on opposite sides of the path, which lost significant roofspace for PV when the main roof faced north. Instead, we propose to face all of the Sunslopes south, and instead develop layouts with entrances on the north side. Here is one possibility. Image 16: (Image 9 is the perspective drawing for this. see for more.) We d move the fireplace to the (duplexable) side and make other changes, of course. 14

14 In general, this means that units on the south side of the path would have their BRs facing north (as well as east or west depending on which side of the duplex they occupy) and therefore in part facing the public path. Privacy concerns for the first-floor BRs could be mitigated by appropriate fencing or plantings (also some first-floor BRs might actually be studies for some residences); privacy concerns for the second floors should be no different than for the residences on the north side of the path. Actually we think this could also be an advantage: while some people might prefer a unit that fronts on the main path, some others might prefer a unit whose living spaces front on the woods. This way there are options for both. If main entrances were on the sides of all or most units, then approaches (walkways, decks) could be from either direction. - Design enables both private outdoor spaces and sociable multi-unit outdoor spaces ( clusters ). With a simple square footprint for the duplexes, more use of fences and plantings will be necessary to shape outdoor spaces. (With offset layouts like image 13, the buildings themselves create more interesting and positive outdoor space.) Still, this should not be hard. If the units open on the side/corners, then each unit forms a natural square with three other facing units image 17 which is the basis for a sociable cluster. 15

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16 4. Other features Here are some further points mostly attractions we consider notable about Sunslopes. - Sloped ceiling creates expansive effect for Great Room without much unused space (as opposed to a two-story vault). In FHA discussions, it seemed that many of us like a high ceiling effect in LRs, but many also did not want to build such big unused spaces (if a whole extra story high). This roofline basically splits the difference: we get a nice lift but not a lot of extra heated but unused space. - Balcony: correspondingly, the main space is quite interesting (image 10). Some parts of the second floor can be open to the first, so the spaces are connected. A ledge for art and/or plants could be put in along the balcony or at ceiling level under the higher parts of the roof. If there is a worry about noise, or wish for more privacy or separation, the upstairs could be more walled off. Or, internal windows could be used to give residents flexibility. - Porches and decks. Porches and decks could be added at many places, depending on how residents want to relate to path, woods, etc., and of course on passive solar needs (either for blocking sun or allowing it in). Image 9 shows an exterior second-floor balcony as well (or these could be screened porches). - High screened porch. A story-and-a half screened porch could readily be included on the north sides. The shorter roof could just be extended for this, or a 1-story porch could be added. (There s the suggestion of a porch on the left side of image 5 and in floorplans in images 11 and 13.) For houses on the north side of the main path, these would be semi-private porches; on the south side, they d be fairly public. Again, residents could select their preference. - Sleeping lofts. Some of us like the idea of being able to sleep outside much of the year. Sunslopes with high screened porches could invite this by building small sleeping lofts out from the upstairs BRs under the porch roof. Given the roofline, these would be loft-like, not with fullheight ceilings (or perhaps they d need a small dormer). They d be optional, but would be a fun way of using part of the upper regions of the high screened porches. - Attic. There could be some attic storage space over the upstairs bedrooms (or those ceilings could be sloped/high too). - Varied sizes: As noted above, we would have to work out versions of this design for various sized residences. Most of the designs here are for 3BR. However, a 2BR (one couple?) version is possible by moving the kitchen into the great room space while narrowing the whole unit, with a small BR or study downstairs and a single somewhat larger BR upstairs. We have floorplans for both 2BR and 1BR versions from the web. 17

17 - Shared house. At the other end of the size scale, a shared house with ~5 BRs/suites could be created simply by taking the duplex layout (image 11) and removing parts of the middle wall. One longer great room could be created (with one end maybe used for a BR/suite, with sloped roof or storage above), one stair, nice balcony sitting area, and 3-4 BRs upstairs. Please note that this would be extremely easy to do: same footprint, same roof, similar rough internal layout. The shared house would not need an extra design of its own. - Variations: If we wanted to, we could create more visual variety by building a few duplexes in an offset layout (image 14) rather than simple ones. If we wanted still more variety, we could also allow/invite some units with simple south-facing shed roofs at the same pitch, which should harmonize well with Sunslopes. 5. Q & A Here are some questions that may come up, with our best answers. Q: This isn t the simplest possible roof. Why not a shed roof? A: A shed roof over two stories like this would get very high (2.5 stories at the high side), losing the relatively human scale of the Sunslope, where the highest edge is only 1.5 stories. The cottage style would not have such a high edges, and the FHA roofline we picked in the end is marked by the goal of keeping the edges only a story high. (Also it is hard to see how to make the floorplan take any decent advantage of the shed roof s lift though probably there are ways.) Q: OK, why not a plain gable roof? A: A plain (symmetrical) gable would have equal size roof halves and so would not offer as much roofspace for PV. Also, a symmetrical gable over two full stories would mean very high roof edges all the way around. However, this could be done on a few units. Q: Why not a full 2 stories rather than a half second story? A: Again, it would be tricky to get such a big south-facing roof over a full two stories, and the roof edges would be high all the way around. In addition, as noted above, the half second story creates much more interesting internal spaces. Q: How does Sunslope compare and conrtast with the FHA Schematic Design? A: Sunslope simplifies the two roofs proposed by FHA, attaching them into a gable and eliminating the large clerestory. For light in the upper BRs we can add in smaller dormers or skylights or skytubes, keeping the upstairs from overheating. The main roofs are larger than FHA s and all face south. The Sunslope duplexes are squarer in footprint, as our new site plan has moved away from the strong east/west axis in the FHA site plan and therefore in the duplexes. 18

18 Q: Won t all the big roofs seem overwhelming? A: We ll need a good drawing of the village as a whole to begin to visualize this. They ll certainly be prominent. In our view this might be consdered an advantage rather than a problem. After all, they ll mostly be supporting PV thus visually affirming our energy independence and reliance on reneweables. On the other hand, one of the potential Design Partners to whom we have been speaking has suggested dividing the one big roof in two, with a raised upper section and a small clerestory/continuous dormer in between, for more light and more visual interest. In section: Varying colors, windows (transparency), and othe elements could also help mitigate things. All of this is very preliminary in any case. The main idea is that there are multiple ways to break up the severity of the large roofs, if need be. Q: Are there other major potential issues with this basic design? A: One other issue might be relatively high noise levels carrying from down- to upstairs, or vice versa, on account of the sloped roof. We have spoken to some owners of saltbox houses who actually consider this an advantage, e.g. families with young children, but others would be concened about it, especially in shared houses where a high degree of privacy may be desired in BRs. There are various easy solutions to this, such as walling off the upstairs (also creating somewhat more space upstairs). Another would be internal windows, giving the option of openness or privacy and again adding to the visual interest. Q: What do potential Design Partners think about this basic design? A: AW has shared earlier versions of this proposal with two potential Design Partners, both of whom would be happy working with a Sunslope basic design. Both also immediately had a number of suggestions, improvements, tweaks, etc. (which, happily, were pretty much the same). That s why we need them! Q: Why Sunslope? A: We d been calling this design a modified saltbox, but that didn t seem very appealing or even descriptive. As we have been saying, availability to the Sun PV is the prime design 19

19 imperative for this design. The big south-facing roof drives a lot of the rest of it. Slope, meanwhile, captures what we like about both the human scale outside (one-story roof edges) and the lift of the large living space inside. Outside, the slope on which the village will be built will itself become a kind of major sun collector, so the village as a whole could also be called Sunslope. 20