Wall
- EPS shipping box · 50 mm (assumed)R 1.32
- Plastic storage tote · 3 mm (assumed)unknown
Known-layer resistance: 1.32 m²K/W
Design class: ReuseValidation status: Data validated
EPS Core in Plastic Shell
A foam box placed inside a larger tote: the plastic protects the foam from rain, sun and outside scratching while the foam insulates. The entrance is cut through both, aligned.
A warm shelter that gets damp can be worse than a simpler one that stays dry.
“Data validated” means only the data and calculations are checked; the model has not been built or tested physically.
Capacity1–2
Outside size700 × 480
BuildBeginner
Time (estimate)30 min–60 min
This model has no 3D view; the drawing and dimensions below fully describe the construction.
Who this is for
- For people with reused material who can check its condition and history.
- For one cat (up to 2), including community cats.
When not to use it
- For young, old, sick or unacclimated animals without extra protection and supervision.
- With material that has not passed the reuse checklist.
Tools and calculations
- Required tools
- Utility knife
- Budget class
- Ultra low
- Location
- Exposed outdoor spot
- Supported calculations
- Geometry, Bill of materials, Cost estimate, Drawing, Build guide
Geometry
Dimensions
| Outside size (W × D) | 700 × 480 mm |
|---|---|
| Height front / rear | 420 / 420 mm |
| Raised off the ground | 100 mm |
| Interior | 500 × 300 × 250 mm |
| Entrance | 1 × 150 × 150 mm, sill 80 mm |
| Chambers | 1 |
| Geometry type | schematic envelope (assumption) |
Bill of materials · compiler output
What you have and what to obtain
Quantities come from the model geometry; items marked as assumptions are planning allowances. Reused material must pass the checklist.
Fill in “My workshop” to see what you still need to buy.
My workshopMaterialNeededOwnedStatus
EPS shipping box1 pcs–Buy
Plastic storage tote1 pcs–Buy
Heavy-duty tape1 pack–Buy
Bricks5 pcs–Buy
Straw1 bale–Buy
- EPS shipping box1 pcsfrom geometry · A clean shipping box with lid; a wall of about 50 mm is a planning assumption.
- Plastic storage tote1 pcsfrom geometry · A waterproof outer tote that holds the foam box.
- Heavy-duty tape1 packassumption · Secure the lid from the outside.
- Bricks5 pcsassumption · Four stable supports under the corners.
- Straw1 baleassumption · Loosely to a quarter or half of the height; keep the rest dry for refills.
Layers and thermal
Known and unknown layers
Partial estimate: some layers are unknown, so no U-value is calculated. Only the resistance of known layers is shown.
Floor
- EPS shipping box · 50 mm (assumed)R 1.32
- Plastic storage tote · 3 mm (assumed)unknown
Known-layer resistance: 1.32 m²K/W
Roof
- EPS shipping box · 50 mm (assumed)R 1.32
- Plastic storage tote · 3 mm (assumed)unknown
Known-layer resistance: 1.32 m²K/W
Not included
- Air leakage through the entrance and joints
- Thermal bridges through battens, edges and fasteners
- Moisture, condensation and property changes of damp material
- Heat produced by the animal
- Wind and transient temperature changes
Assumptions
- Thin layers without a sourced λ (roof covering, film, mat) are not counted.
- A wall of about 50 mm follows ASPCApro's description of roughly 2 inch coolers; measure the real thickness.
- Lid fit and the entrance opening are not modelled.
The estimate is not a temperature guarantee and does not claim the shelter is safe to any temperature.
Water and moisture
Weather exposure
A warm shelter that gets damp can be worse than a simpler one that stays dry. This is an explanation, not a condensation calculation.
- Ground contactRaised about 100 mm off the ground.
- Rain splashHigh enough that rain splash from the ground does not hit the floor.
- Roof drainageThe lid is flat: water runs off to the sides. It must close well and the entrance must not sit below a drip edge.
- Rain at the entranceThe entrance sill is 80 mm above the floor.
- DryingCan be opened to dry out and change bedding.
- Absorbent materialInterior surfaces do not absorb much moisture.
- Maintenance accessAccess for checks and cleaning is simple.
Local price profile
Cost estimate
Quantities come from the model. Prices are not fabricated: enter what you actually pay locally and the estimate stays in your browser.
EPS shipping boxA clean shipping box with lid; a wall of about 50 mm is a planning assumption.
1 itemRSD 0Plastic storage toteA waterproof outer tote that holds the foam box.
1 itemRSD 0Heavy-duty tapeSecure the lid from the outside.
1 itemRSD 0BricksFour stable supports under the corners.
5 itemsRSD 0StrawLoosely to a quarter or half of the height; keep the rest dry for refills.
1 itemRSD 0Estimate from entered pricesRSD 0
Sheet, XPS, framing and hardware quantities come from the compiler. The estimate still excludes delivery, tools, labor, local taxes and unforeseen losses beyond the stated allowances. PROVISIONAL and product-specific items remain explicitly labeled.
Placement
Check the spot
No obvious issue detected
This is not a safety certificate for the spot: it only means none of the listed questions is ticked.
Bedding
What goes inside
- RecommendedStrawRepels moisture and stays loose. Replace when damp, compacted or soiled, and when seasons change.
- Not recommendedHaySoaks up moisture, turns cold and can mould. If already in a shelter, replace it with straw.
- Not recommendedBlanketAbsorbs and holds moisture; a damp blanket chills. Wash and swap as soon as it is damp.
- Not recommendedTowelAbsorbs moisture like a blanket. Wash and swap as soon as it is damp.
- Not recommendedWood shavingsPartly absorbs moisture. Change when damp or compacted.
- Not recommendedWashable dog bedDepends on fabric; textile absorbs moisture. Dry or swap as soon as it is damp.
- Not recommendedNo beddingNothing to absorb moisture. Not applicable.
Maintenance
Inspection schedule
- WeeklyCheck that the straw is dry and loose; replace it when damp or compacted.
- WeeklyCheck for water or dampness on the floor and walls, especially under the entrance.
- After stormsAfter rain or snow check the interior and the ground under the shelter.
- WeeklyCheck for scratching or chewing of the foam; protect or replace damaged parts.
- WeeklyCheck the plastic for cracks and sharp edges around the opening.
- Each seasonQualitative: plastic and foam become brittle in sunlight; replace them when they fade or crumble.
- WeeklyCheck that the lightweight shelter is still weighted or secured.
- After stormsClear snow from entrances and exits so the animal cannot be snowed in.
- Each seasonClean the interior; service access must allow cleaning without dismantling.
Upgrade path
Where to go next
Each step states what you add, what you gain and what stays limited. A new model has a new plan ID; changing an existing build has no canonical plan.
Previous step: Foam Shipping Box Shelter
Don't have this material?
Plastic storage tote
All substitutes and material limits - EPS shipping boxThe substitute changes the construction (thickness, strength or water protection); parts and joints must be re-planned.
- Old pet carrierThe substitute changes the construction (thickness, strength or water protection); parts and joints must be re-planned.
Build sequence
Build steps
Progress is stored in this browser against the exact plan ID; it works offline once the page has been opened.
0 / 7steps completed
Check and clean the box
Use only a clean foam box with no fish, medical or chemical residue and a lid that fits well.
Cut the entrance
Cut a 150 mm × 150 mm opening through eps shipping box, with the sill 80 mm above the floor so rain and snow stay out. Face the entrance away from the prevailing wind. Cover or sand sharp edges.
Put the box inside a tote
Place the foam box inside a larger tote and cut an aligned entrance through both. The plastic protects the foam from rain, sun and outside scratching.
Secure the lid
Tape the lid on the outside and weight it with a brick so wind cannot lift it.
Raise the shelter off the ground
Set the shelter on four stable bricks, about 100 mm above the ground, so the floor does not touch cold, wet ground. Check that it does not rock.
Add straw, not hay
Loosely fill straw to a quarter or half of the interior height. Do not use hay, towels or blankets in an outdoor winter shelter: they absorb moisture and chill.
Choose the spot and secure it
Set it against a wall or fence, out of the wind, away from roof runoff and roaming dogs. Weight or secure lightweight shelters. Check the spot with the placement checklist.
Provenance
Sources and verification status
A source supports a guideline or material value, but it does not confirm this specific model. Container sizes are assumptions and build time is a planning estimate.
- Data validatedcurrent
- Geometry validatednot confirmed
- Engineering reviewnot confirmed
- Physical prototypenot confirmed
- Field validationnot confirmed
ASPCApro · Tier 1Winter Shelters for Community Cats: FAQs and Cold Weather TipsSupports small insulated shelters, cat-sized entrances, elevation from wet ground, straw bedding and predator-aware entrance decisions.Alley Cat Allies · Tier 1How to Build an Outdoor ShelterStep-by-step tote-in-tote shelter: an approximately 30 gallon outer tub, an approximately 20 gallon inner tub, a thin foam slab under the inner tub, straw (not hay) and one tube entrance through both tubs. No elevation height is specified.Alley Cat Allies · Tier 1Straw, not Hay, for Outdoor Cat SheltersStraw repels moisture while hay soaks it up and can mold. Loosely pack straw to the quarter or halfway point; store spare straw dry and off the ground.U.S. DOE Building America Solution Center (PNNL) · Tier 1Typical R-Values and Vapor Retarder Classifications of Common Insulation MaterialsTypical R-value per inch: EPS 3.8-4.4, XPS 5, polyiso approx. 6, fiberglass batt or board 2.5-4, mineral wool board 3-4. Šapice converts these to planning λ ranges (λ = 0.0254 m / (R_IP × 0.1761)); a product datasheet always takes precedence.