TINY HOUSE DESIGN

Introduction

The various defining characteristics of our tiny house includes the ability to adapt and be placed in many different locations with different weather conditions, soil materials and other factors. For the purpose of this project we wanted to provide a location that showcases the many features our tiny house. In order to do that we have to use a specific location, especially when describing elements such as photovoltaics (solar panels), which involves specific angles and unique location characteristics.

Location

Mooney’s Bay Park [2960 Riverside Dr], Ottawa, ON K1V 8W6, Canada.

Coordinates: 45.3684 Degrees North, 75. 6925 Degrees West

In our Revit file we were able to create a topographic surface representing the conditions of Mooney’s Bay Park, unfortunately there will be some discrepancies in our topography but the idea was to simply convey how our tiny house would appear when placed on a certain location, and how certain factors would impact the tiny house, such as sunlight, trees (shadow), and land properties.

Vegetation

The image on the left displays the trees within the vicinity of the house. As you can see, none of them are close enough to produce a shadow that hits the house, meaning there is no need to calculate tree height and sunlight angles. An umbrella is placed on the patio of the house if the residing individuals are in need of some shade.

Motivation

"A tiny house is a brilliant concept that provides a unique solution to many problems."

Economical

Cost-wise a tiny house is the perfect option. It is cheap to build, cheap to operate, and if sustainability features are installed (like solar panels) the cost to operate the house is decreased significantly.

Size + Mobility

Other than cost the adaptability of a tiny house, capable to be installed in countless different locations easily is a unique characteristic. Generally tiny houses can be easily constructed at low cost in materials and labor. Moreover, due to the small size of tiny houses, small plots of land can be used for tiny houses to be placed on, increasing the number of options in location exponentially.

Self-Sustainability

Due to the acceleration of our global population in the near future large homes would not be a practical option anymore both in cost and the use of precious land. Efficient building must be incorporated into urban design. Therefore, houses that are self-sustaining or close to that mark and small in overall area would be the logical solution.

Use of Renewable Energy Technology

Since most houses presently are not self sustaining, designing a house that not only can create its own energy supply, but minimizes the energy usage within the house itself is of the utmost importance. In order to save our global resources architecture must be on a path towards self-sustainability. Tiny houses are a perfect solution; because the space of the house is reduced, electrical appliances are reduced, as well as air space which lessens the use of air-conditioning. Solar panels is the key to self-sustainability because sunlight is our one inexhaustible resource. However, due to the efficiency of current photovoltaics a certain solar panel surface area to house size must be implemented, giving tiny houses the distinguishing factor.

Conclusion

It is because of the reasons listed above that we created a house that is approximately 380 square feet in surface area. We decided to build the house in light-frame wood construction in order to not only decrease our economical costs but have a structurally sound house design. We designed the entire interior of the house, including rooms and furniture specifically to accommodate two adults, as specified in the project, fitting the ideal concept of a tiny house. Moreover, sustainability features such as cross-ventilation, photovoltaics, thermal bridge reduction, and many other features all used to reduce energy usage, and help provide a comfortable living space using the most natural and self-sustaining possibilities offered to us under the parameters of the project.

Sustainability Features

Photovoltaics

PV Calculation Definition: Calculating how much energy our tiny house can obtain through the use of photovoltaics. (Solar Panels)

Due to the location of Ottawa, the best possible angle for solar panels is 45 degrees, giving solar panels a consumption value of 1250kWh/kW.

Canadian Solar C56P-260P panels are used, and they have 16% efficiency. 22 of these panels are then placed on the roof at 45 degrees to maximize sunlight receptivity, and each of the panels generate roughly 260W of power, with a surface area of roughly 1.6m^2.

With this information we are able to calculate the potential energy our solar panels can provide over a timespan of a year:

P = Power Output

P = 260W x 22 = 5720W / 1000 = 5.7200kW

Eprod = Energy produced per year

Eprod = 5.7200kW x 1250kWh/kW = 7150kWh

Therefore, our tiny house is able to provide approximately 7150kWh of energy per year, which makes up for about 77% of our houses’ energy consumption.

Fireplace

The fire place in the living room travels all the way up to the roof, providing heat to the entire house, reducing electrical AC usage.

Glazing

The maximizing of windows placed around the house allows natural sunlight to provide illumination during the day, reducing artificial light usage until nightfall, lowering electrical consumption.

Material Selection

No Red List materials published in the Living Building Challenge are used in the house.

Cross Ventilation

Louvre windows are placed on the east and west walls of the house, so that wind flows naturally around the house, with hot air escaping to the top louver.

Natural Heating

Geothermal heating in the basement reduces heat energy consumption.

Natural Cooling

During the summer if you keep the trap door leading down to the basement open, the cold air in the basement will enter the main floor, reducing the need for air-conditioning.

Technology

Light-frame Wood Construction

We decided on light-frame wood construction for the tiny house. Reasons include how cheap it is for labor and materials, as well as the strong, stable characteristics wood construction allows through the use of joists and studs within the walls.

Overall rectangular design of the house was decided in order to simplify the load path trajectory, strengthening the overall design of the house. A rectangular design also allows us to utilize as much available space as possible. Limiting the first floor to approximately 290 square feet and the loft floor to 100 square feet keeps the entire floor area of living space under 400 square feet, keeping to the guidelines of the tiny house project.

Space saving techniques utilized in our house includes features such as limiting the house to only one interior enclosed room, which also reduces the number of walls. Moreover, ladders leading to the basement and loft floors help minimize space usage (stairs would take up way more space).

To reduce thermal bridging, a simple wall configuration is used for the south, east, and west walls. The amount of studs used for windows are reduced, with only king studs put under the windows to hold them up. Moreover, a double layer header is used for the windows (and the 2-panel sliding glass door) again to reduce thermal bridging. Studs are doubled for the 2-panel sliding glass door, and also holds up the load of the loft floor, increasing structural integrity.

Breakdown

Basement Level:

Floor Size (Approximately): 308 square feet

Room Size (Approximately): 1,540 cubic feet

Description

Basement room is designed to provide space for mechanical systems for both functionality and sustainability features included in the house, such as a water heater, and an energy storage system that’s connected to solar panels.

Lighting

Small windows are installed into the foundation walls at the top in order to allow natural light to enter, reducing electricity usage when accessing the basement level during the day. Artificial light is also available if needed.

Accessibility

Trap door on main floor level opens upwards, allowing an individual to descend a ladder attached to north side foundation wall. A vertical ladder maximizes floor space rather than stairs leading up to the main floor, and due to infrequent needs to access the basement floor a ladder design appears to be sufficient.

Insulation

With the walls of the foundation level being concrete, the thermal conductivity (k) ranges between 1.4-2.9. Windows placed on the northwest and east sides help create cross ventilation for the basement level.

Main Level:

Floor Size (Approximately): 280 square feet

Room Size (Approximately): 2,520 cubic feet

Summary

Main floor level contains the main living space for two individuals. A bathroom, kitchen area, closet, and living room makes up the interior. A sliding 2-panel glass door opens onto a L-shaped patio, with stairs leading down to ground level. Louver windows meant for cross ventilation are placed on the east and west walls of the house, so that wind flows naturally around the house. Moreover, the main hallway leading from the bathroom to the living room is placed by the sliding door making it easier to navigate through the main floor.

Bathroom (Northeast End of Main Floor)

Floor Size (Approximately): 60 square feet

Description

A small yet functional bathroom with all the additions needed, including a shower, sink, mirror, toiler, shelf, and both a washing machine and dryer which are put in the bathroom in order to save space as well as to contain noise generated by the machines from reaching the rest of the house.

Shower

Designed to save space (bathtub takes up too much room).

Toilet, Sink, and Mirror

Standard and flexible to accommodate many different styles.

Appliances

Washing machine and drying machine for laundry, placed in bathroom to reduce noise pollution from reaching the rest of the house.

Shelf

Provides lots of space for storing bathroom accessories and other items if needed.

Lighting

Natural lighting allowed by window on the north side (curtain can be added allowing privacy). Artificial lighting is installed at the centre of the ceiling preferably.

Insulation

The window allows airflow in the bathroom

Closet (Southeast corner of main floor)

Floor Size (Approximately): 9 square feet

Description

Closer space accessible through a bi-fold two panel door (best possible door for a limited size), which reduces the door-path. The interior space could be used for various accessories, such as clothes, shoes, and appliances like a vacuum. Placing the closet right beside the bathroom allows quick access when preparing for the day.

Kitchen + Dining Room (centre of main floor)

Floor Size (Approximately): 60 square feet

Appliances

Oven, Stove, Refrigerator, all placed close to each other (including washing machine and dryer on the bathroom side of interior wall), reducing energy consumption, with the electrical outlets being placed close to each other.

Description

Along with all the appliances, there are four main cupboard spaces for kitchen accessories. Two chairs along with a dining table allows two individuals to eat.

Living Room (west side of main floor)

Size (Approximately): 80 square feet

Description

Two couch-chairs are backed up towards the north wall, with a small coffee table in front of them, and a TV centre at the south wall. A fireplace is placed against the west wall, providing light and heat to the interior.

Patio(L-shaped enclosing the southwest corner of house)

Size (Approximately): 280 square feet

Description

The patio can be accessed from the main floor through a 2-panel glass sliding door.

The glass curtain walls on the south side right beside the glass sliding door allows direct sunlight to reach the interior during the winter, heating up the main floor. On the patio there is a grill, a long lawn chair, as well as a table with an umbrella attached, with two seats accompanying. All materials are rain proof and steps lead form the patio to ground level, exiting the tiny house.

Loft Floor

Floor Size (Approximately): 100 square feet

Description

Small square platform built on top of the bathroom and closet on the main floor. A double bed for the two individuals living in the house Is placed at the northeast corner of the loft.

Alongside the bed is a desk with a desktop computer functioning as a workplace/office area.

Accessibility

The loft is accessible through a mobile ladder that can move side to side so as to not disturb operations on the main floor below. The mobile ladder also does not touch the ground, cancelling the friction between the ladder and the ground, both preserving the surface of the floor and allowing an individual to comfortably step onto the ladder with ease.

Gabel Dormer

The dormer is placed to allow a window to be installed, letting in direct sunlight to the bedroom. Curtains can block off the window to allow privacy, and cross ventilation is increased throughout the house with another window option on the loft floor. Moreover, the extra window allows natural sunlight to illumine the desk/work space, reducing artificial energy consumption.

Roof

A slanted one-panel roof measured at 45 degrees covers the house.

Materials include an asphalt finish, thermal rigid insulation, a vapour retaining membrane, wood sheathing, softwood, and gypsum wall board to finish off the interior surface. Wooden trusses are included within the roof to increase structural integrity, and the roof is completely waterproof with strong insulation properties.

A total of 22 Canadian Solar C56P-260P solar panels are placed on the roof, with the PV output calculated in the Sustainability section. The 45-degree angle of the roof allows the solar panels to fit comfortably on the roof surface, and due to the slant of the roof facing south, maximum sunlight receptivity is achieved.

The overhang of the roof blocks direct sunlight from entering the house on the south side during the summer. The latitude angle of Ottawa is 45 degrees, and when you combine that with a maximum declination angle of 23.5 during the summer you get 68.5, which is the altitude of Ottawa. Since the formula to find the overhang is tan (90 - altitude) = length of overhang / height of window, the calculation is as follows:

Tan (90 – 68.5) = 2/H

Tan (21.5) = 2/H

0.4 = 2/H

H = 5 feet

Therefore, with the height of the glass curtain wall at 9 feet overall, more than 55% of the window will be covered in shade during the summer, enough to shield the upper body of two adults living inside the tiny house.

Energy Consumption

The area of our house is approximately 380 square feet, or 116 square meters. A general energy consumption value for efficient homes is approximately 80kWh/m^2. Therefore, the potential energy consumption of our tiny house over the period of a year (Econs) would be:

Econs = 116m^2 x 80kWh/m^2 = 9280kWh

As listed in the Sustainability Section, the solar panels make up for about 77% of the yearly energy consumption, which is quite efficient for a house with a size of 380 square feet.

Model: What were we able to accomplish in Revit:

We were able to create different levels for a structure and figure out which material suits which floor best.

Wall thicknesses and insulation materials, as well as all the different components that go into walls, such as studs and joists.

How to incorporate furniture and functional appliances for comfortable living.

How to create architectural sheets displaying plans, sections, and elevations, along with valuable information about the house itself.

Increasing out knowledge of various materials, and learning which material is best for which type of wall, floor, and roof.

How to create a one panel slant roof, as well as a gable dormer.

In order to hide the joists and studs from the exterior view, we were able to manually move them and design all the studs and joists going into each wall ourselves. (Thanks to the modules for ARCC 2202)

We were able to manually move the roof trusses downwards so as to not stick out of the top of the roof. Realistically the house should have trusts going through the centre of the roof plate, but unfortunately the ends of the trusses still show at certain viewpoints in Revit, but we were able to do what we could to put them the appropriate location.

What we weren’t able to accomplish in Revit:

There were no options to put joists in for the floors unfortunately, so we had to create floors with different material layers within them, but without joists and beams going through them.

Some studs and trusts are still visible at certain viewpoints in the 3D perspective in Revit unfortunately. As you zoom in on the house you are able to see everything in detail, but we weren’t able to do anything about the fluctuations in viewpoints.

We tried to increase the height of the north wall studs to reach the roof trusses, but unfortunately we were unable to do so because Revit would not allow us to put joists into the roof plate to meet the trusses.

We were also unable to incorporate electric and hydro systems within the framework of the house because we don’t know how. Bathroom installations were simply files we placed into the room, so we were not able to place any piping. Also with electric fixtures we are unable to weave any electrical circuitry within the walls to create on/off switches and lighting installations for our tiny house in the Revit file.

Advantages of using Revit

Revit allows us to not only create an accurate design that fits into all the parameters reality dictates for architecture to provide, but also gives us lots of flexibility to freely design whatever type of structure we wish. The vast categories of materials, along with detailed building strategies all in a 2D and 3D rendering program really allows architects to allow their creativity to take shape.

Limitations of Revit

What constituted for most of our time when using Revit to design our tiny house was trial and error. Learning how to use the program took some time, but whenever we tried to add the next element of our house, in a step by step process, Revit requires users to go about their design in a very specific way. If we forgot one step in the process, errors would appear and we spent a lot of time fixing problems with our house than adding detail to our house. This is the main thing we found disappointing with Revit.

Conclusions and Final Thoughts

Through this project we were able to creatively design a house with restrictions. In previous design projects we were never really given a parameter as tight as the rubric for this project. Having to fit in so many different components within a <400 square feet house meant for two adults really helped us improve our architectural perspectives.

We were also able to go into great detail on both the material and construction methods of a tiny house. In previous projects we never really got into as much detail as we did on this project. Learning about insulation materials, as well as what materials is best suited for which climate, location, thickness, etc... Construction methods such as light-frame wood construction which we used for our tiny house also helped us retain a clearer picture of how a house is realistically constructed, giving us a more in-depth understanding of architecture.

We were not satisfied with only creating a one story house with a boring design. We were actually able to distinguish the various spaces in the house each with its own unique purpose (the living room, the kitchen/dining room, the bathroom, the bedroom, and the patio). Giving the layout of the house some real thought really makes the tiny house more appealing to clients.

We were able to figure out how much our roof should be extended in order to shield individuals staying inside from direct sunlight during the summer. From what we have learned in class we were able to calculate exactly how much extra roof we needed (2 feet) in order to keep 55% of the southern wall shaded. Learning the sun angles not only helps us with human accommodations, but also with photovoltaics. Knowing that every location on earth is unique in reference to sunlight is so useful in architectural design.

What we weren’t able to incorporate

In our original design concept, we wanted to install a skylight. However, a skylight did not serve any practical purpose other than allowing in direct sunlight as an aesthetic installation. Yet during the summer direct sunlight will only heat up the interior of the house (greenhouse effect), so we decided to remove the skylight so as to keep the interior space cooler during the summer in order to provide a comfortable living space for the residing individuals.

LED lighting was something we really wanted to add to our tiny house, but we could not install any type of lighting fixture or circuitry into the house so this was something we were not able to accomplish. LED lighting would be a great choice because of its efficiency to energy consumption ratio. It also does not contain toxic substances unlike other lighting fixtures.

If we could re-do the project over, we believe that we would try to incorporate the lighting and hydro systems into the house somehow. Also the ability to add beams and joists into the floors of our tiny house. Other than these limitations we faced we believe that we were able to address all the different components needed to create our tiny house in reality.

The Revit training modules overall were very helpful to us. In a step by step basis we definitely relied on all the modules to design our house. If we were to state any skills we learned outside of the modules, one example would be learning how to create a gable dormer. Creating a patio with columns going into the ground also required us to learn individually. Stairs and ladder installation was also something we had to look up. Youtube tutorials were extremely helpful throughout the process. Other than the examples listed above I believe the tutorials really helped us get enough of an understanding of Revit to start our project and slowly get more in depth with our understanding of the program.

After using a digital design tool for the first time we believe that digital design has a lot of potential. Obviously it is frustrating at first to learn all the different components of the program, but the possibilities of digital design are endless due to the fact that reality can be conveyed in digital form, giving us the ability to let our imaginations come into reality through pixels. Hand drawn approaches will always be the more familiar method to us of course, but I believe that digital design programs allow us to create so much more, and in less time than it takes to hand draw our designs, which is a crucial factor in architecture.