Thursday, 16 July 2020
More Words About Land and House Features
We looked at so much land before settling on the Stowe property. It was a fun search and, according to folks who live up here, they were extremely blown away that we were able to find a place when we did and for what we got. I attribute this mostly to going up in mud season which is the time in VT when the snow is melting and the roads aren’t yet open to big vehicles due to the snow melt creating giant muddy morasses all over the place. We didn’t find it too bad and it was definitely the tourist off-season. The land we found was put on sale right before mud season started so we got the jump on people coming up in the spring to look for a place to build their dream ski chalet.
If you look at the property, north is on the left, south is on the right. Our property goes from the road on the left side all the way to the driveway on the right (which is actually on our property technically and is protected legally by an addendum to the deed. Beyond the driveway is a big pond owned by the guy down the street a bit. It’s hard to tell just how big the land is by looking at this but you’re driving for a good 40 seconds before you get to the spot where they are going to do the curb cut. It’s just dense woods along a gravel road. The only people who really need to use the road are the people who live there – a far cry from the busy motorcycle raceway we currently live on.
The “thumb” area of the map is the house site. There is a proposed driveway on the diagram and we’ll probably do something like that. We’re still working on grading plans for that. The thumb area is large. If you look at the picture above. I took that from about 2 car lengths in from the road and the property continues to the treeline in the distant fog. Beyond that is the wetland. If you can picture that, then you can apply that same size model to the “finger” side of the mitten. There is a ton of land that isn’t wetland and just wandering woods waiting to be explored.
The main house orientation for our house will be to the right side of the map (pond side) which is south. That’s also the side of the roof that will have the solar panels on it.
If anyone has questions on buying land, I’ll try to help or at least tell you how it went for us. Also to get an idea of taxes, the land as it is now is costing us $5000 a year or so. Once the house is built, I suspect it will be between $19,000 and $26,000 a year. Yowchhhhh.
So far our process has been this: Tell the architect / interior desinger / builder what we wanted in theory
- Net zero or passivehaus if possible.
- Solar as only form of power (no propane for heat)
- Self-sufficient off-grid operation if possible
- Age-in-place for the most part (all main house functions are on the 1st floor)
- Fireplace as a concession to aesthetics over efficiency
- A ton of pantry space and storage
- Some extra room for when the older kids visit or friends come to visit
- A place to keep the TV that’s out of the main living area
- Area outside for a garden with good light and access to water
- Quick hookup for a generator (because a bad snow storm could knock out electricity and water pump uses an electric pump)
Over the next 6 months or so the architect “built” various versions of this house for us using design documents and we made choices.Each round honed the ideas and helped us better understand what we were getting into. Some things came into focus as we went through this process. Many of them started on the first day at the site, before we even bought it, with the architect.
South facing windows are super important for a passivehaus or really any house looking to be energy efficient. There are ways to make less ideal sites work but as we were starting out fresh, having a south facing wall would be key. Passivehaus design generally has a wall of large windows facing south with an overhang above them. When the sun is high in the summer, the sunlight is blocked from entering the house at its highest and hottest. During the winter, the sun hangs lower in the sky and the light will come into those big windows and heat the surfaces inside.
So windows are a big thing for a netzero home and you shouldn’t skimp on them because they are one of the most important elements of the house. Especially in a bitterly cold environment, the need to have light to heat the house coupled with not losing heat out of the glass surface is a major issue. Here are the windows we are buying. There is a 3 month lead time for windows and doors right now which is wild.
Other names you’ll hear are Marvin, Klearwall.
Heating, cooling and power are the next big topic. To get to netzero you need to size your heating and cooling load such that you have sufficient amounts of both but not so much that you oversize your systems (thus drawing more power then necessary). To get to a fairly educated guess, there are services you can get that will run models on your designs and give you expected values for your needs. Luckily for us, there is a group in Vermont called Efficiency Vermont which is funded in part by the state that will run those models for you and help you size and source (locally) heating and cooling systems. We sent them the design documents and they ran them through their models which gave us a hopefully-good first guess at heating and cooling needs for the house.
Here’s an example of an estimate from an HVAC contractor bidding on the job. Keep in mind that the house is currently around 2450 sq/ft.
- 1-Mitsubishi 42,000 BTU Cold Climate heat pump Condenser Requires 50 Amp 240 Volt breaker
- 1-Mitsubishi SLZ-KA12NA Ceiling cassette 13,482 BTU’S of heating for the whole 1st. Floor master bedroom end
- 1-Mitsubishi SLZ-KA09NA Ceiling cassette 10,112 BTU’S of heating for the whole 1st. Floor living/dining/Kitchen area
- 3-Mitsubishi MSZ-GL06NA Wall mounted cassette 6,741 BTU’S of heating for the office, Kid’s bedroom & Guest room
- 1-Mitsubishi PAC-MKA50BC Branch Boxes for Refrigerant piping distribution to the indoor units & to the outdoor units
- 2-Mitsubishi MHK1 Wall mounted wireless thermostats for all the 2 ceiling cassettes
- The 3 wall mounted cassette comes with handheld remote controls
- Refrigerant Piping from the Condenser to the branch box then to all 5 indoor units Condensate piping to the outside or a nearby drain line
- 1 Stand and 1 pad to set on and to keep the heat pump condenser up out of the snow
- We take care of all the low voltage control wiring between units But we will need 240 Volts 50 Amps for the condenser
- and 120 volts to the branch box which will be located in the mechanical room
- Installation of a Zehnder Q350 ERV and an Electric heater on the incoming air that will need a 220V 20 amp circuit
- Installation of all the flex to the register boxes for a total of 18 flex lines, Installation of all the grilles for supply & Exhaust
Since the only power source we have planned for the house is solar (other than emergency backup) we need to make sure that system is sized appropriately. The problem with a lot of this is that we can only model and try to build with some extensibility in mind. We can build with only as much forethought as the models provide some of this is guesswork which is a scary feeling since these could be $50k mistakes.
The solar panel system we designed should provide us with about 12.37 MWh yearly. We are spending an extra $1000 to make sure the system is sized such that we can expand with another panel if needs change down the road. It’s far cheaper to spend that $1000 now than another $12k later. This is a grid-tied system meaning that our electricity is fed back to the electric company and they give us credits. We wanted to build an off-grid system but that looked like it was going to add another $30k to the house cost which seemed extravagant for what it was going to provide.
I should extrapolate on that since it was a big misconception for me when I first started this journey. Building an off-grid modern home is complicated. If you are in town limits, some places have regulations against being totally off-grid and require you to tie into the grid in some way. If you are allowed to do it, your biggest concern then becomes power storage. Batteries are very expensive right now and some designs (like the Tesla) have serious concerns regarding the chance of a fire if certain conditions are met. You need to size the system to store enough power for long periods of low sunlight OR will need to have a standby gasoline generator to charge them when there’s not enough sun. You can get smart systems that kick the gas generator on to charge the batteries when the amount of solar generation is low and your battery charge is critical but generators are loud and require fuel which creates another issue (how much fuel do I need and how do I get it to my house?). When you add all of these things together, it just was a bridge too far for us to deal with. Not to mention the added cost. And the goal was to be assured of power during an outage and the outages are rare up on the mountain and fairly short. It’s just not worth the added tens of thousands of dollars to mitigate that risk. If things go really bad, we are planning on making it easy to tie the house’s electrical system to a gas generator that hopefully gets rarely used.
Here’s what the evaluation for the currently designed system is telling us:
What your solar array saves in one year
- Carbon Offset (lbs): 18,690
- Gallons of Gasoline: 956
- Trees Saved (tons): 4.46
- Computers Powered: 96
- Tons of Coal Not Burned: 2.49
Appliances in a netzero home are pretty straightforward. Our choice is an induction cooktop with an electric oven. We would love a propane or gas cooktop but having no fossil fuels in the house was important and it also reduces another system that can fail. One thing to keep in mind with an induction cooktop is that you need pots and pans that are metal and that can conduct magnetic energy. We mostly have compatible pots and pans already so it shouldn’t be an issue for us but if you have expensive copper pans or things like that, you might have to invest in new cookware.