Intimate scale · Nature · Americas
Rancho Mastatal
Researched and sourced by hand. Last reviewed 2026-08-06.
Rancho Mastatal at a glance
Rancho Mastatal is a hotel in Mastatal, Puriscal, Costa Rica. We read what it publishes about the eight things a building does to your biology and scored the evidence 9 of 24. Last verified 2026-08-06. Materials and Textiles is its best-documented pathway; nothing is published on Air Quality.
Each pathway scores 0 to 3 on the quality of the evidence published, not on the quality of the property. Open a row for every claim and its source.
Air Quality at Rancho Mastatal: Not published (0/3)
0Not published, 0 of 3.
Not published0 of 3 · Filtration, ventilation and what the air is measured at.
We looked for published information on Air Quality and found none. That is a gap in the public record, not a finding about the property.
What is not published
- What filter grade is fitted to guest room air handling, for example MERV 13 or HEPA H13?
- What is the fresh air supply rate per person in a guest room?
- Are carbon dioxide, particulate or volatile organic compound levels measured, and are the readings published?
- Is there a mould inspection and remediation protocol, and when was it last run?
- Are there gas cooktops, fireplaces or other combustion sources inside guest rooms?
Water Integrity at Rancho Mastatal: Claimed (1/3)
1Claimed, 1 of 3.
Claimed1 of 3 · Source, treatment, tested panels and how drinking water arrives.
What the evidence shows
- Claimed
The property states that the water at Rancho Mastatal is potable and asks guests not to bring disposable water bottles, with no source, treatment step or test result described.
The water at Rancho Mastatal is potable, clean and delicious. Please do not bring a disposable water bottle to the Ranch unless you plan on taking it with you when you leave.
PublishedRancho Mastatal, Health and Safety. Checked 2026-08-06. Archived copy from 2026-08-15.
What is not published
- What is the water source, and what treatment is applied before it reaches a guest room?
- Is there a published contaminant test panel, and which laboratory ran it?
- Is shower and bath water filtered, and to what specification?
- How are pools and spas sanitised, and is the chemistry published?
- How is drinking water delivered, and is it treated on site?
Light Rhythm at Rancho Mastatal: Not published (0/3)
0Not published, 0 of 3.
Not published0 of 3 · Circadian lighting specification, flicker, blackout and daylight.
We looked for published information on Light Rhythm and found none. That is a gap in the public record, not a finding about the property.
What is not published
- Is guest room lighting tunable or circadian, and what specification is published?
- What colour temperatures are used in the evening, and are fixtures flicker free?
- Do sleeping areas have full blackout, and is it specified?
- What daylight access does a typical room have?
- Is exterior lighting shielded or reduced overnight?
EMF Harmony at Rancho Mastatal: Claimed (1/3)
1Claimed, 1 of 3.
Claimed1 of 3 · Wired versus wireless topology, and what is measured where people sleep.
What the evidence shows
- Claimed
The property publishes that there is no WiFi network at the Ranch and that internet access is available only to a guest carrying their own phone on the local Kolbi cell network.
The Ranch does not have WIFI.
PublishedRancho Mastatal, FAQs: Is there internet in Mastatal?. Checked 2026-08-06. Archived copy from 2026-08-15.
What is not published
- Are guest rooms wired for data, or is access wireless only?
- Where are wireless access points and smart meters placed relative to the bed?
- Have field levels been measured in sleeping areas, and by whom?
- Can a guest have wireless disabled in their room on request?
- Is any shielded cabling or shielding material specified in the build?
Materials and Textiles at Rancho Mastatal: Specified (2/3)
2Specified, 2 of 3.
Specified2 of 3 · Named materials, finishes, bedding composition and cleaning chemistry.
What the evidence shows
- Specified
The property names the material palette used to build its guest structures: bamboo, cob, wattle and daub, light clay, natural plasters, and wood and stone from surrounding forests and rivers.
We construct with bamboo, cob, wattle and daub, light clay, natural plasters and wood and stone sourced from the area's surrounding forests and rivers and design/build all of our own edifices.
PublishedRancho Mastatal, Accommodations. Checked 2026-08-06. Archived copy from 2026-08-15. - Specified
Interior finishes are named per guest building, including lime and clay plaster at Bernie's Bunkhouse, earthen plasters and earthen floors at the Starboard Cork, tadelakt showers at La Malanga, the Honey Hut and La Casucha, and a bamboo floor at the Hooch.
Bernie's Bunkhouse is a beautiful timber frame, wattle and daub, lime/clay plastered building that has 3 rooms, each with 2 sets of bunkbeds.
PublishedRancho Mastatal, Accommodations. Checked 2026-08-06. Archived copy from 2026-08-15. - Specified
The property names the lime products used in its plasters, renders and paints, stating it previously burnt quicklime from a regional kiln into lime putty and now buys powdered hydrated lime, and names the plasterers who developed its techniques.
In the past we have used burnt lime (quicklime) purchased from a regional kiln, to make our own lime putty, we now buy powdered hydrated lime. These two products can both be made into plasters, renders and paints.
PublishedRancho Mastatal, Natural Building. Checked 2026-08-06. Archived copy from 2026-08-15. - Specified
The property states that all timber in its structures is sourced and milled within its region and often from the Ranch property itself.
All the wood that we utilize in our structures is sourced and milled in our region and oftentimes from and on Ranch property.
PublishedRancho Mastatal, Natural Building. Checked 2026-08-06. Archived copy from 2026-08-15.
What is not published
- What are the mattresses made of, and are they treated with flame retardants?
- What is the fibre content of the linen, and is it certified, for example to GOTS or OEKO TEX?
- Which paints, adhesives and sealants were specified, and are they low emission?
- What cleaning and laundry products are used, and is the list published?
- Are there named low emission certifications on the flooring or joinery?
Food and Kitchen at Rancho Mastatal: Specified (2/3)
2Specified, 2 of 3.
Specified2 of 3 · Sourcing, on site growing, cookware, kitchen water and additive discipline.
What the evidence shows
- Specified
The property publishes a sourcing share figure, stating that almost all food comes from within Costa Rica and that over 80 percent comes from within ten miles of the Ranch. The figure is the property's own and no verification is published.
We source almost all our food from within Costa Rica, and over 80% comes from within ten miles of the Ranch.
PublishedRancho Mastatal, FAQs: What's the food like?. Checked 2026-08-06. Archived copy from 2026-08-15. - Specified
The property names local lard as its cooking oil, states that local meat is served once a week, and states that eggs and cheese come from neighbouring producers.
We serve local meat once a week and use local lard as our cooking oil and often serve dishes made with our neighbors' eggs and homemade cheese.
PublishedRancho Mastatal, FAQs: What's the food like?. Checked 2026-08-06. Archived copy from 2026-08-15. - Claimed
The property states that every meal is prepared by hand from whole foods and that the kitchen owns neither a can opener nor a microwave.
Our food is sourced from our local and regional foodshed, and each meal is prepared by hand from whole foods. We do not own a can opener. We do not own a microwave.
PublishedRancho Mastatal, Farm to Table and Fermentation. Checked 2026-08-06. Archived copy from 2026-08-15.
What is not published
- What share of produce is grown on site or sourced locally, and is it verified?
- Which cooking oils are used, and is the policy published?
- What cookware is used in the kitchen?
- Is kitchen and ice water filtered, and to what specification?
- Is there a published position on additives, preservatives or allergens?
Biophilic and Healing Design at Rancho Mastatal: Specified (2/3)
2Specified, 2 of 3.
Specified2 of 3 · Nature access, views, volume and natural material contact, designed with intent.
What the evidence shows
- Specified
The property publishes that it designed and built all of its structures apart from two it renovated on arrival, across an infrastructure of more than 30 covered buildings, and attributes the design and build approach to the Yestermorrow Design/Build School.
We have over 30 covered structures that make up the Ranch infrastructure a number of which are sustainable homes. Aside from two buildings that we renovated upon arriving to Mastatal, we have designed and built all of our structures.
PublishedRancho Mastatal, Natural Building. Checked 2026-08-06. Archived copy from 2026-08-15. - Specified
The Main House lodging is published as sitting on the edge of a 235 acre private wildlife refuge with 7 kilometres of forest trails bordering La Cangreja National Park.
The main house is set on the edge of our 235-acre private wildlife refuge and features close proximity to 7 kilometers of forest trails, abundant wildlife, waterfalls, rivers, swimming holes and beautiful forests that border the La Cangreja National Park.
PublishedRancho Mastatal, Accommodations. Checked 2026-08-06. Archived copy from 2026-08-15. - Claimed
Outlook and immediate surroundings are described per guest cabin, with the Honey Hut published as looking out to forest within an agroforestry planting and La Casucha as sitting on the edge of the rainforest within a food forest.
The space is extremely private and looks out towards the forest and is surrounded by one of the Ranch's agroforestry spaces.
PublishedRancho Mastatal, Accommodations. Checked 2026-08-06. Archived copy from 2026-08-15.
What is not published
- Does every guest room have direct outdoor access or an operable opening?
- What is the published design intent behind the natural materials used?
- What are the typical ceiling heights and room volumes?
- Was the landscape designed with native planting, and is the palette published?
Sound and Sensory Ecology at Rancho Mastatal: Claimed (1/3)
1Claimed, 1 of 3.
Claimed1 of 3 · Measured background noise, separation between keys, and scent load.
What the evidence shows
- Claimed
The property discloses to prospective guests that the Main House, which contains guest bedrooms and a six bed bunk room, is the busiest building on the campus and the place where all meals are served.
The main house is generally the most active place at the Ranch, and where all meals are served, so please keep this in mind if you're interested in staying here. There can be a lot of action here at times.
PublishedRancho Mastatal, Accommodations. Checked 2026-08-06. Archived copy from 2026-08-15.
What is not published
- What is the measured background noise level in a guest room at night?
- What acoustic separation is specified between adjoining keys?
- How loud is the guest room air conditioning at its lowest setting?
- Is fragrance diffused into guest rooms or public areas, and can it be declined?
38 open questions could be answered with information this property already holds. Answer these for this property
Best for, and not ideal for
Not ideal for
- anyone who needs air quality data: nothing is published
- anyone choosing on lighting: nothing is published about it
What is not publishedthe gaps we looked for and did not find
Nothing is published on air filtration, ventilation rate, or any carbon dioxide, particulate, volatile organic compound or mould measurement. The property does publish combustion sources: a cob rocket stove, open fire cooking, an earthen oven in the Main House, and biodigester methane piped to the kitchen. No air measurement accompanies them, and the Main House also contains guest bedrooms. On water, the source, the treatment train, any filtration specification and any laboratory panel are all unpublished; potability is asserted without a test. Nothing is published on lighting: no circadian or tunable specification, no colour temperature, no flicker performance, no blackout provision. On electromagnetic exposure the property publishes only that no WiFi network exists, with no wired topology, no access point or meter placement, and no field measurement anywhere on the record. Mattress composition, linen fibre content, textile certification and cleaning and laundry chemistry are all unpublished. Kitchen and ice water treatment is unpublished. Nothing is published on measured background noise, acoustic separation between rooms, or fragrance policy.
Regional context1 public figure about the area, none of which scores
Public data about the surrounding area. None of it contributes to the score, because a property cannot be marked down for the conditions outside it.
- Safely managed drinking water, Costa Rica: The World Health Organization reports 81 per cent of the population nationally, 80 per cent in urban areas, 81 per cent in rural areas using a safely managed drinking water service. This describes the country, not this property, and says nothing about what reaches a guest room here. It is recorded because it is the background against which a property's own treatment is worth publishing. Source
Verification recordwho checked this, how, and when
Verification record
- Method
- Desk research of published sources, each claim cited
- Reviewed by
- Certified Spaces Standards Inc.
- Last verified
- 2026-08-06
- Changes
- Every correction is logged
Not published is not unsafehow to read these scores, and what this index does not promise
A low score means a property has not published information. It does not mean the property is unsafe, unhealthy or poorly run.
These scores measure disclosure. These scores describe disclosure, not property quality. This index has no commercial relationship with the properties listed unless a badge on the listing says otherwise.
Conditions change, and we will not always know. Every record is a snapshot of what a property had published when we read it, and that date is on the page. Conditions change: a property can refit, change suppliers or replace a system at any time, and nothing requires it to tell us. We re-read records and ask properties directly for updates, but there will always be a gap between what is true today and what was published when we looked. Use this as a frame of reference for what to ask, not as a substitute for asking. Take your own questions to the property before you book, and tell us if you find something we have wrong.
We report what properties publish. We do not inspect, certify or vouch for any property on this index unless a listing says we assessed it on site, and we accept no responsibility for decisions made or outcomes experienced on the basis of what you read here.
Questions travelers askwater, air, EMF, and whether it is worth it
Questions travelers ask about Rancho Mastatal
Does Rancho Mastatal publish water quality testing?
It is claimed but not specified: the property asserts it without naming a system, supplier or measurement. Scored 1 of 3.
What is the air quality like in the rooms?
We can only report what is published about the rooms themselves. No. Nothing is published, and we looked. That is a statement about the public record, not about safety.
Is Rancho Mastatal low-EMF?
It is claimed but not specified: the property asserts it without naming a system, supplier or measurement. Scored 1 of 3.
Is Rancho Mastatal worth it?
We score evidence, not experience. On evidence, it ranks 32 of 70 researched records. The strongest documented pathways are Materials and Textiles and Food and Kitchen; nothing is published on Air Quality or Light Rhythm.