Notification Window

The House on Limekiln Line

By: Lisa Moffitt, OAA Intern

The House on Limekiln Line is off-grid and set in the vast agricultural landscape of Huron County, Ontario. Photo Credit: Shai Gil

Project Name:
House on Limekiln Line

Project Owners:
Maggie Treanor

Project Location:
Huron County, Ontario

Architects:
Designer: Lisa Moffitt, OAA Intern

Project Completion Date:
August 2011

Project Site:
25 acre active farm outside of Blyth, Ontario

Project Type:
Single Family Residential

Project Type Context/Setting:
Rural Agricultural

Other Building Description:
Off-grid house on working farm for single elderly client.

Lot Size:
25 acres {101,000 m2}

Building Gross Floor Area:
86 m2 / 925 sq ft

The House on Limekiln Line, a design-build off-grid house, is sited in a rich agricultural landscape. The house is understood as both a mediator to and a microcosm of its immediate cultural and climatic context.  An “observation shed”, the house is composed of a series of scales of spaces, each with distinct vantage points, visual alignments, and framed vistas to the larger context beyond, facilitating stewardship of and respect for the productive landscape in which it sits.

SUSTAINABLE METRICS:

Annual energy consumption in ekWh (equivalent kilowatt hours):

  • Gross (including solar energy): 9639 eKWh
  • Net (not including solar energy): 8919 eKWh


Energy density in ekWh/m2:

  • Gross: 112 eKW/m2 per year
  • Net: 104 eKWh/m2 per year


Building full time equivalent population: 1

Annual potable water consumption in m3: 48 m3

Annual potable water consumption in l/person: 48,000


 

Carefully calibrated views into and through the house make it feel spatially expansive despite its compact 5.5mx15m footprint. Photo Credit: Shai Gil

The house inventively retains a very compact footprint, limiting its environmental impact, while retaining a substantial presence in the vast agricultural site. The interior of the 85m2 house is composed of a core of service spaces floating within the shed shell. Carefully calibrated views into and through this core ensure that, despite its limited footprint, the house is visually expansive. This experiential choreography, along with careful siting, with crops growing to enclosure, allow the house to act as a place of observation, a space that defers to and reflects back the annually and diurnally shifting landscape beyond. Creating a dialogue with and respect for the local culture and landscape encourages a sense of stewardship towards the larger ecological and environmental processes of the vast agricultural landscape in which the house sits.


Crops grow right up to the edge of the house minimising impact to farming activity and facilitating stewardship of the land. Photo Credit: Gabriel Li

 

 

Much of construction was completed by local farmers with side trades. Photo Credit: Becca Treanor

Conversations about sustainability focus on the triple bottom line: how a project balances social, environmental and economic concerns. Addressing environmental and economic concerns are standard practice for architects. It is more difficult to engage in depth in the social dimensions of local construction practice. The designer moved to the site in order to be involved in construction processes and material selection. Construction of the house was largely completed by local farmers with side trades and materials were acquired from small local suppliers. Exchanges with local farmer/subcontractors honed particular building strategies, techniques for construction, and material selection that built from local knowledge. The house was flat-framed and raised by crane, a process akin to a local barn-raising. The house was both strangely familiar in form due to its reappropriation of barn typologies, but it also offered an alternative to energy-intensive existing tract-home building methods in the region.

Metrics:

Percentage of building population traveling to site by public transit (bus, subway, light-­rail or train), carpool, bicycle, or foot:  0% Not possible in rural context poorly serviced by public transport.

Percentage of building population using transit options other than single occupancy vehicle: 0%

Number of parking spaces (occupants & visitors): 2

House was flat-framed and raised in place akin to a local barn-raising. Image Credit: Lisa Moffitt

 

 

 

 

The house is surrounded on all sides by large-scale active farms. Photo Credit: Gabriel Li

The house sits on a 25 acre working farm. The design of the house and construction staging ensured that disturbance to agricultural production was minimised. All infrastructure for the house is contained to a limited footprint between the house and drive-shed. The house is slab on grade construction, which limited excavation and minimised regrading around the house. 

Crops grow right up to the edge of the completed house. Generous threshold spaces eliminate “yard”, thus maximising agricultural production on site. A generous continuous south deck and a 15 meter long west “deck walk” allow for exterior occupation without disturbing farming activities on the land.

All site infrastructure is contained within a small footprint on the site to minimise site excavation and to reduce disruption to agricultural production. Image Credit: Lisa Moffitt

 

The south deck overhang mitigates summer sun while allowing low angle winter sun to heat concrete floor. Photo Credit: Shai Gil

Siting and orientation facilitate passive heating and cooling. A 2.4 meter continuous south deck overhang ensures that summer sun is blocked, creating a cool concrete floor in summer. In the winter, low-angle sun enters into the house, passively heating the radiant in-floor heating thermal mass concrete floor.

Evenly distributed operable windows facilitate summer cross-ventilation and stack effect heat purging. Summer prevailing winds are from the south/southwest; operable windows on north and south sides of the house facilitate significant cross-breezes.

Triple glazed windows, a highly insulated envelope detailed to reduce thermal bridging, and the use of high efficiency appliances ensure that energy consumption required to service the house is low.

A core of service spaces floats within the shell of the house facilitating cross ventilation and consistent natural lighting of interior. Image Credit: Lisa Moffitt

 

 

Evenly distributed windows on the north and south elevations provide consistent natural light and cross breezes. Photo Credit: Sahi Gil

The house is experientially generous and visually porous. A core of service spaces floats within the shed shell. Strategically placed openings in the core allow views, light, and air movement into and through the house. Windows are evenly distributed around the perimeter of the house. The abundance of natural light and the open configuration of spaces mean that artificial light is never required during daylight hours. Operable north and south windows facilitate cross ventilation through the house. Upper operable windows purge hot air. 

METRICS:

Percent of total building area that is daylit: 100%

Percent of building that can be ventilated or cooled with operable windows: 95%

East/west building section. Image Credit: Lisa Moffitt

 

Site water is collected along perimeter drainage tile and outlet at end of deck walk. Photo Credit: Shai Gil

Due to the expansiveness and natural topography of the site, precipitation is managed through perimeter drainage tile that outlets down slope directly in the field.

Water is supplied by a well on site. Low flow fixtures ensure that water consumption is minimised in the house.

Precipitation managed on site: 100 %

Percent of total water from reclaimed sources: 0 %

 

Electricity for house is provided by a 1.4kw solar array. Photo Credit: Gabriel Li

All electricity for the site is generated using a 1.4 kw photovoltaic array.  The system was sized to supply the house with all of its electrical needs during all but the least sunny months (November and December). A high efficiency back-up generator tops up batteries as needed in winter months.

Solar energy is stored in a battery bank within an insulated box in the drive shed. High efficiency appliances within the house dramatically reduce energy consumption, and consistent natural light eliminates the need for artificial light during daylight hours.

Propane fuels a hot water heater, also located in the drive shed’s insulated box in order to stabilize interior temperature. The hot water, dedicated for in-floor heating in the house, is distributed from shed to house in a high-insulated pipe developed in Scandinavia for comparable purposes. A separate on-demand heater in the house supplies domestic use. Siting of all infrastructure maintained minimum adequate clearances in order to limit footprint of construction and excavation on site.

An insulated space within the drive shed contains inverter and batteries for photovoltaics. Photo Credit: Lisa Moffitt

 

 

(L) Wood for siding, decking and interior counters were harvested from a site within view of the property. Photo Credit: Lisa Moffitt (R) Neighbour transporting siding from barn. Photo Credit: Maggie Treanor

The designer moved to the site to oversee construction, facilitating word of mouth recommendations of small-scale building materials and suppliers, and reducing embodied energy of materials used. Pine siding, hemlock deck framing, cedar decking, and maple counters were all harvested from a lot within view of the site. All waste wood was donated to local farmer for biomass for winter heating. A local agricultural steel siding manufacturer provided steel siding, flashing and custom steel panels for the drive-shed door.

Steel agricultural materials and implements were recycled and/or reappropriated. Steel grating typically used for barn walkways were brake-formed into interior and exterior guardrail panels. A number of interior elements such as steel bases for kitchen counters, perforated grain filters reappropriated into a hanging “pulley” light shade, were reclaimed from a local recycled steel yard. Steelwork was completed by a local farmer with a side trade as a steelworker with the designer acting as apprentice on site.

Steel guardrail grating and steel “pulley light” reappropriate agricultural materials for a domestic use. Photo Credit: Gabriel Li

 

 

Agricultural buildings adjacent to the site. The house resisted the urge to upsize in a context where space and resources are in abundance.  Photo Credit: Lisa Moffitt

Designing for adaptive reuse in this context was at odds with the downsizing philosophy of the design. The space designed is suitable as a residence for one or two people. During construction, there was a general tendency to promote ‘upsizing’ spaces and systems to increase resale value. This tendency was resisted and the smallest available systems were specified; this was particularly the case for the septic and heating systems. This tension between building now to anticipate the future when building standards now may not be the best for the future introduces an interesting paradox for designers to reconcile. The project offers an alternative way of thinking about use of space and resources within a context where resources are abundant; challenging these conventions while also working within the prevailing construction practices of the region was the primary legacy of the project.

Construction processes were informed by those for agricultural buildings. The scale of space and its off-grid and energy saving features offered alternative ways of building in the area. Photo Credit: Lisa Moffitt

 

 

Early digital models testing configuration and extent of south overhang for passive heating and cooling purposes.

Due to the low budget and the small scale of the project, most technical decisions followed best practice guidelines rather than advice from technical consultants. The extent, orientation and configuration of the south deck overhang was an element that was rigorously tested during design development using sunlight simulations in digital model. The extent of the cantilever overhang had structural implications, so minimising its length while maximising its ability to shade in summer and allow light in winter was carefully tested. Following construction, photo documentation confirmed efficacy of overhang to block summer sun while allowing winter sun to heat thermal mass of the concrete floor.

The client continually monitors electricity generated through photovoltaic array in winter months to confirm whether batteries need to be topped up with the generator. She has generally found that electricity generated is sufficient in summer and requires topping up in November and December as anticipated.

Time lapse photographs of solar gain on a typical late Autumn day confirm early digital  modelling studies. Image Credit: Lisa Moffitt

 

 

(L) Lisa Moffitt, (M) Pete Long, (R) Nick Treanor

Designer: Lisa Moffitt, OAA Intern

Builder: Peter Long

Structural Engineer: Cory Zurrell, Blackwell

Off-grid Consultant: Nick Treanor